# Brian's Donkey Engine



## Brian Rupnow

I followed Captain Jerrys Donkey Engine post with great fascination, until alas, it kind of bogged down and came to a stop. Now that I have the capability to cut spur gears, I have been searching thru all of the Youtube postings of Steam Donkey engines, and decided that there are many different types and configurations of said engine. I think I would like to try building one myself, and of course I will post build drawings as I go along so that others may join in the fun if they wish. I don't have any experience with donkey engines, and I don't have one close at hand to run out and measure, but that probably isn't as large an issue as one would think. I have found a youtube video which I will post a link to, and it shows the one I may try to design/model/build. This much I understand---there is a double acting cylinder on each side. The crankshaft is actually a long pinion-shaft that reaches from side to side, and since the engine would have to be self starting, the crank throws will have to be 90 degrees out of phase. I know that the pinion and the very large gear are constantly in mesh, and that the big gear is fixed to the large winch shaft so that the winch shaft turns whenever the engine is turning. The winch itself is supported by bearings which "float" on the main winch shaft, and there is a clutch mechanism (which is explained very well in captain Gerrys article) that transmits torque from the main shaft to the winch drum. This clutch mechanism is operated by a manually engaged lever.---I think the lever and clutch mechanism only has to be at one end of the winch drum. I can't see any good reason that this engine would ever have to go into reverse, because when cable is pulled off the winch drum, the drum can "free-wheel" to play out the cable. Some of this type of Donkey engine was used in mine hoists, and consequently had a large ratchet and paul assembly, but I don't think that was needed on a Donkey that winched logs across the ground. Also, Jerry makes reference to an external band brake which gave him difficulty, and I'm kind of wondering why it was there. To the best of my knowledge, this type of winch only pulled, as you can not push with a wire cable. why then have a brake on it at all? I welcome all discussion, as I'm just getting my head into this thing now. I am not trying to steal any of Captain Gerrys thunder, as his post and machine are excellently done, and mine will be somwhat different. Comments and helpfull hints or theories please.----Brian Rupnow
[ame]http://www.youtube.com/watch?v=VM3qRcWmo-4&feature=player_embedded[/ame]


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## Jared

Hi Brian, 

Looking forward to seeing this come together. The reason for a brake is if you are using it as a hoist you want to be able to hold or lower the load without it crashing down or dragging something up a hill you don't want to give up your hard-fought ground and have it slide back down.

I would suggest the books "In Search Of Steam Donkeys" by Merv Johnson and the reprint of the Willamette Iron and Steel Works 1925 product catalog. They are full of pictures and drawings and cutaway views of Pacific Northwest logging donkeys. Neither one is cheap ($60 or $70 I think) but very interesting. The WISW catalog has parts diagrams of clutches and brakes. If I find someone with a scanner I'll send some pages to you.


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## Brian Rupnow

Jared---that would be greatly appreciated. I have completely "blown my budget" in the last two weeks, purchasing a set of involute gear cutters, a broaching set, an arbor press, two sets of 1-2-3 blocks, and an Ivan Laws book on Gear cutting!!---Brian


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## Dan Rowe

Brian,
Most donkeys had at least 2 drums. They were used to yard or move loads from one point to another point. A single cable can only lift the load in a vertical direction with two cables the load can be lifted and moved. The rigging gets complex and I am not an expert on this type of rigging. Brake drums keep the drum not being powered locked so the haul back line does not go slack and the load moves in a controlled manor.

The Willamette yarders had either Stephenson or Marshall reverse gear. 

Dan


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## JorgensenSteam

I put some hoist info here:

http://www.classicsteamengineering.com/index.php?topic=271.0

and here:

http://www.classicsteamengineering.com/index.php?topic=262.0

You can pick the photos, right click, and save them, or load them here if you want.
It is public domain stuff.


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## Brian Rupnow

Thanks PatJ---The pictures help a lot.---Brian


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## te_gui

They usually have multiple drums with different size cables on them depending on whether they were hoisting or yarding. I helped restore a 3 drum Willamette a few years back. The smallest cable was known as the haywire or straw line drum. It was drug out by hand into the brush, thru a block attached to a stump or other anchor point, and led back to the engine. The light line was then used to pull the much heavier mainline out. This was then hooked to the anchor and the donkey was dragged farther out into the wood. it was quite a job pulling them out 500 yards at a time, and you can see why many of them were abandoned in the woods once the job was over. I know of 2 in the wild here in the northwest, and they are both at least 5 miles in from the nearest road, so recover would be a very expensive proposition.


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## Brian Rupnow

I have been setting here eyeing all of my models, and I keep going back to the Popcorn engine. It is such a smooth runner, and I already have it modelled and detailed. With a bore of 1/2" and a stroke of approximately 1" it is close to the right size. There is a potload of work in that crosshead guide, but it does work so well-----. I really like the shape of the cylinder, and it would be very easy to complete in right and left hand versions to make up a twin cylinder engine. I think I will stick with the single drum version, as per the video posted in my very first post, with an internal expanding clutch ala Captain Jerry, and an external band brake courtesy of yours truly. The flywheels would become much smaller, in fact virtually dissapear, but thats not such a big deal with a twin cylinder double acting engine with the crank throws offset 90 degrees. When I built the Popcorn engine, I was workingf from Stews early plans and converting them to British Imperial, however I got ahead of myself and forgot to "unmetricize" the crank throw, making for an very unususl stroke length of 0.984". If I use that engine as the basis for my Donkey, it would give me a chance to correct that.


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## Captain Jerry

Brian

This will be interesting, to you and the rest of us watching. I watched the video that you linked to and it is a simple looking machine. Its not clear how this particular one was used but it helps illustrate some of the history of these machines. I don't know who the manufacturer was but they all had a lot in common.

They were offered in the bare base model as this appears to be. Two cylinders, pinion shaft with cranks, and a drum. From there you could add components to suit the application. Even though this one does not seem to include drum controls, the drum is a standard casting that includes a clutch/brake drum with ratchet teeth. I don't see any hand control levers or foot pedals so it seems that the hoist drum is fixed on the shaft.

The pawls for the ratchet would seem to be a simple thing to add but it some applications, they could be a nuisance or a hazard.

Internal clutches with hardwood friction blocks engage or disengage the drum from the shaft but were not used the way we use a clutch with a diesel engine. They were "slipped" rarely if ever. The engine was stopped or slowed and the clutch was fully engaged before the engine speed was increased. The clutch might be slipped to take the slack out of the cable but one the load was encountered, the clutch was fully engaged and the load controlled with the engine. Unlike a diesel, a steam engine has full torque at low speed and does not stall in the same way that a diesel does.

A load can be lowered with brakes (usually foot controlled) but could also be lowered by slowing the engine and slipping the clutch. Brakes make it a lot easier, particularly with two or more drums.

By not modeling a particular machine, you will leave yourself a lot of leeway. Add or leave out some feature and you will still be historically accurate. Somebody, somewhere, specified one just like it. Just keep it in the flavor of the time and you will end up with an attractive model.

I'm in for the ride.

Jerry


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## Brian Rupnow

Thanks Jerry. ---I was hoping that you wouldn't be upset that I was contemplating making one of these models. I was fascinated by the progress you had made with yours. I am going to put a clutch on the one I build, similar to what you used, and I think I will probably design a manual band brake. As you did, I will also include a "boiler" that although not actually used will lend an air of "Authenticity" to the model.


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## Brian Rupnow

Scale and proportion---Where do I start? Well, the stroke of my engine is going to be 1", so the crank throw will be 1/2". If you look at the "flywheel" end of the connecting rod in the video, you will see that where it connects to the "flywheel" is about 1/2 way between the center and the outside of the rim. That would make the "flywheel" 2" in diameter. The main large gear appears to be about twice the diameter of the flywheel, so that would make it 3 1/2" to 4" in diameter.The length of my cylinder is fixed, to accomodate the 1" of piston travel, and the distance from the end of the cylinder out to the end of the piston rod at full stroke is now established by the length of cylinder and the stroke. In the attached picture, there is only a slight gap between the front of the boiler and the flange of the drum, which is roughly the same diameter as the large gear. The center of the cylinder is just marginally on the far side of the boiler centerline. The position of the crankshaft relative to the position of the large gear wheel and winch will be established by the pitch diameters of the large gear and the much smaller pinion gear on the crankshaft which engages with it. In both the video and the attached picture, the boiler diameter is equal to or slightly smaller than the diameter of the large winch gear, which makes it roughly 3 1/2" in diameter. The overall width of things will be established by how tightly I can fit the cylinders and valve bodies to the sides of the boiler. That gives me enough information to start laying out the components. I will make a preliminary layout, then compare it to pictures and videos of old existing full size Donkey engines, and move things around until get a good visual match. Thats how i start a project like this.


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## Captain Jerry

Brian

Not upset at all. I am surprised that more people have not built one of these fascinating machines! They are a great part of North American history. Logging, mining, shipping, and any type of material handling adopted these versatile tools. They were the antecedent of the donkey but they were the predecessor of every cable operated crane, shovel, dragline, clamshell, up to the introduction of modern hydraulics. 

The construction site of the World Trade Towers (visible on Google Earth) is dominated by a Manitowoc Crawler Tower Crane. If you were to rip off the sheet metal, the parentage of this huge machine would be obvious. Three horizontal drums, each mounted slightly higher than the one in front of it, with internal expanding clutch, and external brake band. There are additional smaller drums on this machine for boom/jib control and swing but the layout is strikingly similar. I spent a lot of my life in the mining and construction machinery business. I love these machines.

Please feel free to adopt or modify any of the methods that I posted in my temporarily dormant donkey build. That is what this forum is all about. Maybe if you design and post a satisfactory solution to the brake band, it will prompt me to revive my project.



			
				Brian Rupnow  said:
			
		

> Scale and proportion---Where do I start?



You will always wish that you had gone bigger! That is about the scale that I used and I found myself dealing with (PITA) #0-80 fasteners. (PITA) to stay in scale. I had one of those double lens jewelers magnifier attached to my glasses. If I haven't already said so, they were a Pain In The A..., oh, I already said that.

Jerry


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## tel

> Maybe if you design and post a satisfactory solution to the brake band, it will prompt me to revive my project.



'Imitate the actions of the ....' dept Jerry - have a good study of the kickback brake on a chainsaw!

Interesting project Brian - reviving my interest in doing one.


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## Brian Rupnow

So tell me guys---In the units with more than one winch drum, does each drum have its own individual brake and clutch mechanism?


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## Captain Jerry

Brian

The answer is "yes". The pinion gear engages both big drum shaft gears so both drum shafts are turning anytime that the engine is running. Either or both of the rope drums can be engaged by the operator.  A lot of skill and coordination required.

Jerry


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## Jared

The other way you can do it is to have the pinion driving one drum and the other drum driving off the first one. This causes them to turn opposite directions so then you wind the line on the top of the back drum and the bottom of the front. Another variable that you can play with is the gearing and drum core diameters. Most yarding donkeys used in logging had the back drum (mainline) geared so it turned slower and pulled harder than the front drum, which was geared faster and had a larger diameter core for speed since all it had to do was return the rigging to the guys in the brush.



			
				te_gui  said:
			
		

> I helped restore a 3 drum Willamette a few years back.



te_gui, where's that yarder at? Is it in running condition?


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## Brian Rupnow

Okay guys---This is sorta, kinda, it. Overall proportions are going to be very close to this. Length of winch drum may grow a little, and I definitly have to come up with a main base. I will probably come up with some other kind of crosshead guide, but the jury is out on that for right now. Thats a 90 tooth gear on there, which works out to about 3.83" diameter. Overall, I don't think it looks too bad.---Brian


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## JorgensenSteam

Brian-

You won't be able to adjust the valve stem very easily with those steam chests turned towards the inside.

Pat J

Edit:

I am looking at the old engravings, maybe that was how they did it.

Edit 02:

For some reason, I thought I remembered the steam chests facing out in the old engines, but they do not. The steam chests on the old engines are further forward on the frame than your design, so that the steam chest covers can be removed without removing the boiler.


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## Jasonb

I thought that as well, maybe move the drum forward of the crank and then the boiler can be moved towards the crank and the valve chests will then be behind the boiler.

J


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## Captain Jerry

Brian

That looks good. You might think about reducing the drum spool diameter and making the flanges straight sided. Drum capacity was a factor where the log haul was very long. Wooden lagging staves could be added to the drum to increase the line speed if desired. Straight flanges make that easier. The flanges were usually pierced with bolt holes to make adding and replacing the lagging easier.

I like the looks of the X-head guide and there is historic precedence for it. I just can't remember which maker used that style. 

Jerry


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## SBWHART

Hi Brian that looks real good, i like your idea of actualy putting an engine to work, I've long toyed with the idea of coupling an engine up to a rolling mill.

I thought my popcorn engine was a little small on the cylinder bore, I put a pressure gauge onto the air line to see what it took to run it and got 10 psi and 20 psi with the governor connected, with all my other engines they will run at less than 3 psi, the over crank wone the competition and runs at 1psi, It may be worth considering increase the cylinder bore by couple of mm, there is enough room to take this without having to increase the overall size of the cylinder.

Stew


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## Brian Rupnow

Pat and Jason---I have to agree with both of you. What will actually happen is that I will increase the distance between the cylinder and the crankshaft, thus moving the cylinders out farther to the left from the centerline of the boiler. What I have shown in that quick "lash up" was based on the rod length on the original Popcorn engine. If you look at the picture in post 310 you will se that that donkey uses a much longer connecting rod. Jerry---That style of crosshead guide was used on many "factory horizontal" engines. As far as the bore is concerned, the 1/2" bore is more than enough when you consider that it becomes a two cylinder engine in this configuration. Here is a configuration with longer con rods and much improved access to the valve bodies.


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## Steve J

Brian
  I am in the process of making the two drum steam donkey from the plan book by Willaim Harris from Village Press. It is a pinion drive to both spurs , has a rachet disc on both drums and a brake band on both drums. The brake bands are made of hose clamp bands with over center devices to tighten them up. Am on page 14 of a 54 page plan book so have a way to go. There are also capstan drums on both winch drums which I think are keyed to the axle so they will pull when the clutch for the drum is disengaged. 
                          steve


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## JorgensenSteam

Brian-

Looks good.


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## tel

... or you could get really anal and try this .....


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## Captain Jerry

Brian

I hope you don't mind all of the advice, but if you proceed with the latest plan, you will have limited the machine to a single drum. To power a front drum, the pinion/crankshaft has to be in front of the main drum. 

I don't think you need to worry about removing the steam chest. American Hoist cast the steam chest integral with the cylinder and used the steam chest (with an integral flange) to attach the unit to the deck. The cylinders were hung outside the deck frame. Just the steam chest cover needs to be removed to set the valve. You might need more room to see but unless you are building a live boiler, you will have plenty of room for setting the valve by removing the dummy boiler.

As to the X-head, I am familiar with that type in many applications. What I should have said to be more clear is there was at least one manufacturer of steam donkeys that used that style so it would be historically accurate as to style but not in all detail. The one that I remember seeing looked more like the one you used on your twin horizontal.

Steve:

The capstans are keyed to the shaft and turn when the engine turns. They were operated by a helper who would throw two or three turns of rope on the drum and manually tail the manilla or hemp rope to control the load. The drum turns but does not pull the rope until the helper applies tension to the tail. Not a place to use wire rope. Usually used on a yarder or gin pole application to swing the boom. Precise control of the boom required the helper to use both drums and to slip one against the other to swing right/left/stop.

Jerry


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## Captain Jerry

Hear is a rear view showing the outboard mounting of the cylinders hanging from the steamchest.







Jerry


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## cfellows

Great looking project, Brian. I'll be following along!

Chuck


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## Harold Lee

Brian - I have building a Steam Donkey on my bucket list as well. A couple of years ago I went to Hillsboro Oregon and visited with Merv Johnson who wrote the book "In Search of Steam Donkeys". My grandson and I spent the day with him. He has a trailer sized model of a donkey and we spent a bit of time with it. I also went to a logging camp (Camp 18) which is on highway 26 at milepost 18 on the Oregon coast and spent time there photographing and measuring many of the donkeys they have there. One of the original donkeys had a single cylinder vertical engine and the drum was horizontal. They were interconnected by a large bevel gear much like a cement mixer. Village Press also put out a small book "The Steam Donkey Engine" by William Harris that has a set of plans for building one.
http://bay-com.com/product-info.php?pid164.html
If there is anything I can do to provide you with information, Please let me know. I'll be following your build with great interest.

Harold

PS - I'll contact you off list for some additional information.


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## joe d

Brian

There are two donkey engines on display at the Logging Museum in Algonquin Park... gives you an 
excuse to visit your old stomping grounds.

Joe


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## Brian Rupnow

I don't usually do this much "flippin and floppin'" when I first get involved in a design, but its taken a lot of rearranging and moving things about to end up with a model that is pleasing to my eye, allows access to the valve boxes, and more or less resembles one of the original donkeys. I think that a lot of the eye appeal in this model is in the bearing stands and the base, so I have spent quite a bit of time on them. I have altered the crosshead guides a bit and put on a couple of rather nifty looking stanchions to support the outboard end of them. You will never wander down an old logging road and see one quite like this, but then again, this is not intended to be an exact model. This is a model that captures the essence of the old steam donkeys, and will have a functioning winch, clutch, and brake mechanism.----But will still be within the capability range of mid range skilled model engineers.---Brian


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## JorgensenSteam

Brian-

I think you have done a good job of capturing the look and feel of the old steam hoists.

The design is looking very good.


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## tel

The layout looks good to me - very much in keeping with the old 'uns.


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## Brian Rupnow

Here we have it in all its naked glory, without the engines and boiler.


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## Brian Rupnow

Now, for all of you guys that are setting around bored, suffering from mid winter blues, and just dying to begin a new project------. These are all drawings for the Donkey engine that I know are correct and won't change. How do I know?---Because they are the exact same drawings I used to build the Popcorn engine, and it runs extremely well. There are going to be some drawings that I have yet to develop, and actually make the parts before I will turn them loose on an unsuspecting public, but these ones I am certain of.---Brian


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## Brian Rupnow

And here's another bunch of Donkey parts---


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## Brian Rupnow

And more---Damn, there's a lot of parts to a Donkey!!!


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## Brian Rupnow

And my last bit of Donkey Doo for today---


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## Brian Rupnow

My nice long design contract across town is limping to an end. The design work is all finished and I'm just waiting for all the various machined parts and weldments to be completed and brought "in house" so I can supervise/orchestrate the final assembly of the machine. In the meantime, I get to spend quite a bit of time at home, and consequently get to spend day time hours designing my toys. In a way I am covering new ground here, as I have never completely designed a steam chest and slide valve on my own. On all of my previous steam engines I have copied other peoples designs. This time, using the original Popcorn design by Stew Hart as a starting point, I am changing port sizes and eccentric travels, and a host of other related items. I haven't posted drawings of any of these changed items, because I first have to convince myself that the changes I have made will work properly. I'm off now to the bank to pick up a wheelbarrow full of money to buy brass at my local metal suppliers. ;D ;D ;D


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## Captain Jerry

Brian

It's a lot easier to "flip" and "flop" in SolidWorks than it is on Craftex. Thats the beauty of 3D design.


Jerry


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## Brian Rupnow

I have been studying Captain Jerry's clutch mechanism which he came up with for his Donkey engine build. It is indeed a clever mechanism, and there are some vitally important parts that simply don't show up or get mentioned in his posts. I have wore my "engineer detective" hat all morning, and I'm pretty sure I have sussed out how Jerry did it. I am going to post a drawing and a few solid models to show how I believe this clutch works.






View attachment DONKEY CLUTCH SHOW AND TELL.PDF


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## Brian Rupnow

These two models show the components inside the clutch. Of course that purple shaft with the round knob on it which I called an "activation pin" is in there only for "show and tell". In reality it will be a short pin operated by a hand lever to engage and disengage the clutch. There will also be a spring under that sliding hub which under normal circumstances will hold the sliding hub away from the winch so that the clutch shoes don't constantly "drag" on the inside of the winch drum. I will post more about that lever as my design progresses.


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## JorgensenSteam

Brian-

Nice Solidworks stuff.
Once you learn 3D, it is hard to imagine designing anything in 2D.

Looks nice.


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## tel

Hey, I like that clutch arrangement Brian - you're not just a pretty face, are you! (some say not _even_ a pretty face)


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## Brian Rupnow

Well there!!! Thats another 6 hours out of my life that I won't get back.----Modelling clutches. The models do look great, don't they.--Can't really take credit for the design though. Captain Jerry did a remarkable job on coming up with this clutch in his original Donkey post.--I just had to do a bit of detective work to figure out what he'd done. Thats enough for now. I'm off to my metal supplier with a barrow full of money to buy brass.


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## Brian Rupnow

And that, my friends, represents $260 of the finest Canadian dollars!!! I struggled up to the "Pay" counter with all my bits and pieces and damn near fell down dead when the clerk toted up the price. I had stopped at the bank yesterday and got out $100 thinking that would cover it. Now I know why I keep taking design contracts even though I am 65 and theoretically retired. I'm just like a junky, working to support my habit.----There---Now that I've had my little hissy fit for the day---That much money for what will probably be 2 or 3 months entertainment for me probably is justifiable.---Just makes me wish I'd been born rich instead of good looking!!!


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## Captain Jerry

Brian

I hesitate to point this out as I don't want to seem overly critical but there are a few things that you may have missed in my design. I did not emphasize it in my post but the clutch friction plate should expand outward and not be pressed axially against the clutch drum. In the AmHoist design as shown in a photo in reply #22 of my donkey build, the slider at the outer end of the expansion link, has a flange that slides on the gear web and absorbs axial thrust. My version of that slider shown on reply #23 has a similar flange. I also found that the pivot point for the link to slider (outer end of the link) needs to be below the surface of that flange to prevent the whole thing going cockeyed. You will see that on the original as well as my version.

As you will find when you begin to test this winch, axial thrust will cause all sorts of problems. For example, the gear must be prevented from rubbing on the clutch drum flange and the Winch drum which is integral with the clutch/brake drum must be isolated from all axial loads. If I had a half dozen of those nifty little ball thrust bearings, I would use them on this. 

I felt that I had to mention this because that gear and clutch drum represent a sizable investment in brass, as you well know. I worked some of this stuff out in aluminum before putting tool to brass.

Jerry


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## Brian Rupnow

Jerry--I see your point my friend. I have added a second flange onto the top of that green slider, so that it is fully supported on both sides of the remaining gear web. No axial forces at all will be passed on to the clutch discs. Fortunately there is a very small amount of travel in that green slider, so I was able to cut a larger access hole right next to the hub of the gear to get the slider in and slid into place.


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## Captain Jerry

Brian

That's the ticket. I think you might like the action a little better if you move the pivot pin hole in the green slider down to sit between the flanges. That has two advantages. First, it prevents the slider from cocking and binding. Second, if you polish the ends of the pivot pin the sides of the slot in the gear will act as the retainer.

You are renewing my interest in this project. I have a feeling that it won't be long before I get back to it.

Jerry


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## Brian Rupnow

For those of you who like to see "in process" shots, this is the way I start the cylinders. I am machining them from 1 1/4" square stock. I cut them 1/2" longer than I really need, machine the overall rectangular shape to size, and cut away any material that is parallel to the sides. Whats left get set up in the vice, checked for being "true and level" and then I drill and ream the 1/2" bores in place. (When I set them up I had a 3/8" parallel setting under them to provide drill clearance when the drill breaks thru the bottom of them). Still in the same set-up I drill the 4 holes in each one which will be tapped to hold the end caps on, drill the steam gallery that goes thru to the near side port, and mill away some material between this steam gallery and the cylinder so that steam can flow from the gallery into the cylinder when the end cap is bolted in place.


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## Brian Rupnow

Now,----You were wondering why I cut the material for the cylinders 1/2" too long, weren't you. Well, I needed to make some handles for them---and the handles are absolutely not allowed to rotate in the cylinders. After I made up a couple of handles from round scrap (Turned to 1/2" dia. to fit the cylinder bores.), I cross-drilled through that extra half inch of material at the end and put a 3/16" split pin thru both peices to hold the handles in the cylinders. I stuck the handles into my lathe and took a clean-up pass across the face of each cylinder. This makes certain that the end face of the cylinder is perpendicular to the bore. I then set my vernier caliper to the cylinder length I actually want to end up with and scribed both cylinders in the area where the red layout dye is. Why did I need handles?---It will all become clear in my next post.


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## Brian Rupnow

And now you know what the handle was for!!! (If you followed my popcorn thread, then you have already seen this done). It works so neat!! Next thing I will do is set it back up in the lathe and part the cylinder off to the correct length.


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## Brian Rupnow

No progress today. Had to make what seemed like a terribly long drive over to western Ontario to Brussels and see a customer. It was only 360 Km round trip (225 miles) and I did get a new contract, but it was a grey dismal day and I didn't sleep much last night. I would much rather have been tucked up in my nice little machine shop finishing off Donkey cylinders instead, but I've got to do something to keep money flowing so I can keep buying tools and pay for brass!!! : :. ---Brian


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## Brian Rupnow

Hubba Hubba -Ding Ding--Lookit the profile on that thing!!!! : :


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## Jasonb

Brian is it me or have you NOT made a handed pair ??? Surely you should have a left and a right.

Or will they have the same drillings on the other end? making them interchangabel?

J


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## Brian Rupnow

Jason---Shows your thinkin' lad. The cylinders are symetrical about centerline, or ambidextrous, or bisexual, or something like that!!! They aren't right and left anyways. However, the steam chests may be, depending on where the steam inlet is positioned.----Brian


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## Brian Rupnow

Tonight we have a pair of finished cylinders, and a pair of "steam chests to be". Tomorrow I will finish the steam chests and maybe carve out some cylinder end caps. Of course the wisest thing would be to finish one cylinder assembly completely and see if my maiden voyage into port design works out okay---However, faint heart never won fair lady, and its easier to make two of everything as I go along.


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## Brian Rupnow

Who knows if these Donkey type engines had cladding on the boiler? Any videos I have ever seen of the real ones just show a smoke blackened boiler, I've never seen one with cladding.---Brian


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## Brian Rupnow

Jeez, I'm full of questions tonight. Where does one go to get miniature brass or black iron pipe elbows? I'm thinking something that would be suitable for use on a "pipe" about 3/16" or 5mm in diameter. If I do this donkey up the way I'd like to, I want to have the steam pipes from the boiler to the cylinders to make it look authentic. As I'm setting here typing this, I'm thinking "Probably the Model railroad guys have a source for this stuff.----God knows there was enough pipe and elbows on the old steam locomotives."


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## joe d

Brian

PM Research have some nice pipe fittings in a variety of sizes.

Joe


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## Brian Rupnow

Thanks Joe---That looks like it would be just the ticket!! Here's a link to their website----Some mighty interesting stuff.----Brian
http://www.pmresearchinc.com/store/product.php?productid=3273&cat=41&page=1


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## Jasonb

Yes the PM research ones are good, I've bought several of the un machined trees of castings, use them on this, the nutted unions you will have to make yourself. I used 40tpi ME threads.


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## Harold Lee

Brian Rupnow  said:
			
		

> Who knows if these Donkey type engines had cladding on the boiler? Any videos I have ever seen of the real ones just show a smoke blackened boiler, I've never seen one with cladding.---Brian



Brian - The Donkeys I climbed all over in Oregon primarily at Camp 18 http://www.camp18restaurant.com/loggingmuseum.html did not have any cladding on them. I do not remember seeing any with any cladding but that doesn't mean there weren't some built that did. My guess is since these were initially used in the logging industry, fuel was not in short supply and therefore heat loss from the boiler skin was not important. 

I would think when they were later placed into steam shovels and drag lines where they burned coal and oil that they were placed into cabins and perhaps had cladding added at that time not only to conserve the heat but to protect the operators. If you would like I could contact Marv Johnson and ask him.

Harold


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## Brian Rupnow

Thanks Harold---Thats what I thought. Here is steamchest #1 well on its way to "becoming" both in the milling machine and trial fitted to the cylinder.


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## Brian Rupnow

Okay---One steamchest finished!!! That means its nap time.


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## Brian Rupnow

This evenings offering is a gaggle of cylinder end caps. The diameters come out fairly good. The finished thickness of the end caps though, thats another story. According to the drawing they are supposed to all be 0.197" thick. I have one at 0.208, one at 0.203, one at 0.216,and one at 0.178!!!! It is plain that my methodology for turning steps to a finite length could use a whole lot of improvement!!! This is not a particularly critical measurement, and its one of those things where if its not visibly different, it doesn't really matter. The one undersized one is a rod end cap, and I'll have to thin out the other rod end cap to match it, but at least no one will notice and it isn't the kind of thing that demands remaking a part. The chatter marks you see are a direct result of machining with my cut-off tool, which is the only damn thing I have for plunging into round stock and ending up with a square corner. Again though, those chatter marks will be hidden inside the crosshead tube. Its a bit like that old army song "But my socks don't show, and the Sarge don't know, about my dirty undies!!"---I continuously strive to make more uniform and better toleranced parts, as I learn this machining game. I have improved in a lot of areas, not so much in others. I WILL try harder!


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## Brian Rupnow

One cylinder is almost complete. I have to order a box of shorter bolts tomorrow, but at least all the holes line up. (Which is always a great relief to me)!!!--My real job is interfering with my play job, so I didn't get much done today.


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## moconnor

Hello Brian,

Great job as always. I always enjoy following your design progression and your builds.

You mentioned that your parting tool is the only way that you can machine a square shoulder. Do you only use carbide insert turning tools or do you use your own hand ground and honed HSS tool bits?

The best way to achieve a square shoulder is with a combination of turning and facing out (or in to your finished diameter) with the cross slide, using the lathe's built-in 90 degree angle. Of course, this would leave the radius of your tool bit in the corner, which is completely under your control with a HSS tool bit as it is honed on after grinding.

Dinner is ready, must go.

Keep up the great work.

Kind regards,
Mike


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## Brian Rupnow

Mike---When I made those four end caps, I did it by turning the o.d. on a single piece of brass to the largest diameter, then parting them off one at a time. As you can see, there are a number of "steps" in each end cap, and the only way to really accomplish what I did is to plunge blind and depend on the dials for diameter, and also to depend on the dials for travel along the bed. The parts are so short that once cut from the main piece of brass its damn near impossible to set them up individually in the chuck for more work and have them "run true", so I like to get all the turning, facing, drilling, reaming, etcetera all done while the pieces are still attached to the main blank in the chuck. I know I could build a chuck spider or a "purposed collet", but the way I did it works---its just not horribly accurate. ---And Oh yes, I grind my own HSS cutters.


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## Jasonb

Time to invest in some soft jaws me thinks, would easily hold those cylinder covers true so the second side could be machined eliminating those chatter marks. Or just make up a simple split bush to hold them with that has a step to register against the front of the chuck jaws and a back to it to keep the part true.

J


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## tel

Split chucks get my vote - so simple to make, and once you have one for a particular job you could literally face off hundreds of pieces to identical thicknesses. I have quite a stash of 'em now - if they won't fit the next job that comes along they are very easy to modify.


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## tel

Here is a cylinder cover being held in a split chuck




and here is the split chuck




and here is the cover


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## Jasonb

Thats the thing Tel, also very handy for holding gears with tooth counts that are not divisible by 3.

J


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## Brian Rupnow

I'm old but I do have the odd trick up my sleeve.. This is how I trued the end caps up in a secondary operation. I found a short piece of black iron pipe and couneterbored the end for a light press fit of the disc o.d. The c'bore was shallow enough the half the face thickness stuck out past the end of the pipe. This let me "true" all the thicknesses and adjust any diameters I needed to adjust.


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## tel

Now if you had shortened that up a bit, cut a chucking spigot on the other end, and ran a saw cut through the side, you would have a split chuck. The spigot locates against the chuck jaws, ensuring repeatable location, then you lock the X axis feed and face in with the Y for however many pieces you want to do.

Oh, and mark the position of the no.1 jaw, for that bit extra repeatability.


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## Brian Rupnow

Progress was made in leaps and bounds today!!! If the Lords willing and the creek don't rise, I might actually get to make a piston and rod and try one of these cylinders out tomorrow. I REALLY hope they perform as expected.--and yes, those registers with the so ugly chatter marks on them are hidden----they are covered by the crosshead guide tube.


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## Brian Rupnow

Here we are, right into the messy end of the business!!! Last night before going to bed I made up the 3/16" diameter cold rolled piston rods and threaded both ends. Then I turned the cylinders to 9/16" diameter and drilled and tapped them in the lathe, then parted them off from a piece of 3/4" aluminum round rod. I coated the threaded end of the piston rod with 638 Loctite and screwed the pistons onto the rods as far as they would go---even gripped them lightly with my pliers and made sure they were tight against the end of the tread. These sat up overnite under a 100 watt bulb, and this morning the Loctite was fully cured. Then each piston and rod assembly went back into the lathe, the rod in the chuck, and the piston was Oh so carefully turned to 0.500 dia. This is a very delicate turning operation. 0.001 too much left on the diameter,and they won't go into the cylinder bores. -------.001 too much taken of the piston and the damn things fall into the bores. What you see in the picture is the messy business of lapping. Even though the piston will (theoretically) fit into the 1/2" reamed bores, there will still be "tight spots" over the length of the piston travel that must be addressed. To do this, the piston is coaed with 600 grit lapping compound and gently worked from end to end of the cylinder. I find that what works best for me is to set the cylinder on my desk top where I can hold it firmly with one hand, while lifting and lowering the piston rod full stroke, like an old "dash churn" and revolving it about 5 degrees (finger estimate) between plunges. (Not during the plunge) I do this 50 strokes on each cylinder and piston assembly.---And note that when you have a twin like I do, once the lapping is completed, the piston is "dedicated" to the cylinder it was lapped in---don't mix them up after this step!! Next step will be to do a complete and carefull Varsol wash of the cylinders and the piston assemblys to clear out any remaining lapping compound.


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## Brian Rupnow

Now, if I but had some valve cover plates and a whole whack of gaskets we could try this thing out!! One valve is centered nicely in the housing, while the other has a bias to one side. This might cause a problem, but then it may not. There is a certain amount of "float" built into the design of this valve body, so we'll see whan I get some air on it.


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## Brian Rupnow

And yes, virginia, we do recycle the offcuts. and then we even recycle the offcuts from the offcuts!!! With the cost of brass climbing to absolutely insane prices, I would even recycle the chips if I could just find a way to hold them.---Brian


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## Brian Rupnow

Finally, by what I see is almost the end of the day, my reclaimed offcuts have magically turned into a nice set of valve cover plates.---(Resting on a much used and abused 1/4" parallel). That about does it for the physical build of the cylinders. Next up are a full set of fabricated gaskets, disassembly, reassembly, and a quiet prayer.


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## Brian Rupnow

Tomorrow I have to work at one of my "real" jobs (The kind I get paid for). When I do get back to this engine to disassemble it and put in the gaskets, I will put the holes in the steamchests for the incoming steam.---and as someone was concerned about, this will make the cylinders right and left hand assemblies. I could keep both steam chests the same by having the steam enter at the end opposite the control rod, but I think I want to have it enter from the top, same as in the very first video in this thread.--I want to keep my plumbing the same. The walls on the steamchests are thick enough to drill and tap for my fittings that I will be using.


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## Harold Lee

Brian Rupnow  said:
			
		

> SNIP>>>> (Resting on a much used and abused 1/4" parallel). <<< SNIP



Brian - That must be a Swiss made parallel. I think I have seen some cheese that the same company made ;D

Your progress is incredible considering you also have a real job. I cannot work at half your speed and all I have is my shop..... And my spouse.... and my two kids.... and their spouses.... and my six grandkids... 

Keep up the great work. This this will be chuffing away before we know it.

Harold


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## Brian Rupnow

Harold---Thank you. All is not as it seems. I have 3 jobs right now. The spinforming job has been on hold all week waiting for weldments to come in from an outside shop. The job which I can't talk about because I signed a Non disclosure agreement is on hold because I have to get some very proprietary cutters made up at an outside company. The reverse engineering design on the curb machine is temporarily delayed because of customer cash flow issues. This of course means that even with 3 concurrent jobs on the go, I get days where all I have to do is play in my toy shop.----Brian


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## Brian Rupnow

This is the one part of making model engines that never seems to get any easier.---Making gaskets!! I have made up a number of dedicated weapons to help me in this quest, but its still a pain in the butt. Yes, printing them off at 1:1 scale does help if you use a light colored gasket material that you're not afraid to put thru your printer, but its not THAT MUCH better than the old "Trace around with a pencil" trick. The difficulty lays more in cutting them out and not having them tear out at the very narrow margins between bolt holes, pressure gallerys, and outside (as in atmosphere). Oh, I get it done-----it just takes time. I have tried all of the different blends of gasket goo, but my engines are generally apart 5 or 6 times before they go together to stay, and that instant gasket stuff doesn't like that too much, and its very difficult to keep the damn stuff out of places that you don't want it. The gasket material I use is about .025" thick, and is very forgiving if you have to disassemble something a few times to tweak it.


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## Brian Rupnow

A big thank you goes out to the gentleman from Indiana who sent me the brake details. I could have sussed something out on my own, but seeing how others approached the task makes it a lot easier for me.-----Brian


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## Blogwitch

Brian,

I would suggest you try some PTFE sheet for your gaskets.

Since using it (for a few years now), I have never had a gasket break, like paper does after many assembles and disassembles, and also I have never had it leak, absolutely wonderful stuff.

http://madmodder.net/index.php?topic=1054.msg8338#msg8338

But do make sure that you buy the virgin sheet, without any etching on the surface.


John


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## Steve J

Brian
  Glad to hear you got the brake details. sometimes all it takes is a glimpse of the way the other guy did it to have it all come clear. I am working on brake drums at present and then will be winch drums to mount them on.
                             steve


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## Harold Lee

Brian - You might find a leather punch will help make some of the smaller holes. I have on it it really makes part of the task easier. You can find them in the local craft stores or online.

http://www.google.com/products/cata...T4eFHcWvgwfv29CWAg&ved=0CFoQ8wIwAA#ps-sellers

Looking forward to seeing you progress.

Harold


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## Brian Rupnow

Thanks John. I will try and source some of that material in this end of the world.---Brian


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## Maryak

Brian,

Not trying to teach you to suck eggs, but you will have fewer gasket Oops if you punch out the holes before you cut the shape.
Like most things this was another I learned the hard way.

Hope it helps

Best Regards
Bob


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## Brian Rupnow

Got home tonight from one of my "real" jobs, and decided that I simply HAD TO come up with some steam inlet pipes to try these cylinders out!!! I looked at using 3/16" diameter brass tubing, but was kind of underwhelmed by how it looked. I modelled them and tried them on in the model, and somehow they just looked too small in diameter. I have a bunch of 1/2" brass hex rod that a good friend gave me, so I turned some of it to 1/4" diameter and drilled it out to 1/8" i.d.. I threaded one end to 1/4"-28 and then mounted the cylinders to a dummy baseplate and drilled and tapped the steamchests while everything was assembled (of course I had removed the valve slider and rod). I did this to ensure that the steam inlet tubes were absolutely verical. I didn't want them to "lean" in any direction when assembled to the final baseplate. Tomorrow I will install all the gaskets and see if it flies.


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## Jasonb

Brian if you are going to be plumbing this one up with the cast fittings you could end up with a very chunky looking plumbing system using 1/4" od pipework, if you look at the pictures at the start of this thread the pipework would proportion down to something much smaller.

You should still be able to get 1/8" bore using 3/16 pipe and a finer 40tpi thread which would suit the exhaust side of things and come down to 5/32 with 3/32 bore for the delivery side of things maybe even 1/8" pipe.

Just out of interest Model Engineers handbook says a 5/32" OD pipe will supply enough steam for a 1" bore x 2" stroke cylinder so no risk of restricting the flow.

J


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## tel

Agreed - in copper 1/8" for the steam and 3/16" exhaust is more than adequate for the 3/4" bore engines. _Perhaps _1/4 copper for the exhaust for a bit more 'vacuum'


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## Brian Rupnow

This morning I have GREAT NEWS for all who are watching this thread. The port modifications that i made worked good, and both cylinders respond excellently to the action of the valve. Now I am free to go ahead and build the rest of the engine, without having to worry about putting a lot of work into a project and then having it fail because the new port design wouldn't let the engines run.---Brian


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## Harold Lee

Looking great Brian... I think we will have a runner!!!

Harold


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## Brian Rupnow

Now that I have convinced myself that the changes I made to the cylinder porting does indeed work, I can now go ahead and post those drawings which were affected by my changes.


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## SBWHART

Brian

Have you worked out the throw of the cam for the slide valve. ???

Just ran you're figures through the vormula I use and I'm strugling to get the same answer as you, or see how the valve would work.

I take it you're trying to use standard imperial cutters of 1/8" and 3/16" I think these are a little big for that steam chest

Better to use 3/32" and 1/8" cutters which is closer to the 2 and 3mm cutters used on the popcorn

With these cutters your .282 will be .234 on the valve vace

And for the slide valve.657 will be .623 and .345 will be .375

Hope this helps

Stew


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## Brian Rupnow

Stu--I worked out the throw for the cam and it is 0.172" throw, a total movement of 0.344".


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## Jasonb

The large size Benson that I have just got running uses 1/8" & 3/16" ports at the same spacing as your 0.282".

But the cavity under the puck is 0.423" long, total length of puck 0.75" and the eccentric throw 0.117" and it runs fine on 10psi and thats a much bigger piston & stroke.


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## Brian Rupnow

Well there!!! Thats enough machine shop magic for me today. Tomorrow I will carve out the sides of the crosshead guide tubes for that "Oh so cool" look. Now---Concerning the ports.---I wanted this cylinder to be buildable without having to buy metric endmills. I have accomplished that. Does it work?---Well, it certainly works in the video. Is the throw on my cam going to be sufficient unto the task?---Well, I think so, but no, I'm not 100% sure, untill I've seen it run on its own. Did I apply a lot of scientific principles when designing this change?---No, not really. I seen what Stu had done, and it worked succesfully. I seen what a couple of other folks had done, and theirs worked succesfully. I made some block diagrams and seen what ports were covered and uncovered at different times in the cycle. I used some of Stu Harts math. I crossed my fingers and buried a black cat in my backyard at midnight. If the worst thing that happens is that I have to make a second cam because the first one I designed doesn't work (Which I doubt will happen), it won't be the end of the world. I'm not exactly certain what type of mania made me make the center port longer than the ones on each side, but i think it was the old "adjustable centerline" that got me. I would probably look at that a little more closely the next time. Hey, I'm happy!!! it works.


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## SBWHART

Jasonb  said:
			
		

> The large size Benson that I have just got running uses 1/8" & 3/16" ports at the same spacing as your 0.282".
> 
> But the cavity under the puck is 0.423" long, total length of puck 0.75" and the eccentric throw 0.117" and it runs fine on 10psi and thats a much bigger piston & stroke.



I got very close to these sizes when i ran it through my maths (.438 and .748) for 1/8 and 3/16 ports. 

If you've done the cad simulation and and it looks OK it probably is OK Brian, we can keep our fingers crossed and hope the black cat comes up trick.

There is more than one way to skin a black cat, and these engines have a fair bit of tolerance for air running its not as though we're running a pumping station with them where ever bit of effieciency matteres.

Its a great project Brian and very interesting.

Stew


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## Bill Gruby

I just finished going thru all 7 pages of this project. It is fascinating to say the least. Now caught up I won't miss any more.

 "Billy G"


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## Jasonb

Brian Rupnow  said:
			
		

> I wanted this cylinder to be buildable without having to buy metric endmills



On small engines its possible to just used drilled holes for the port face and not worry about machining slots which allows you a lot more freedom with sizes (benson is drilled as you can see )

If you are going to just run this on air I'm sure things will be OK but if the boiler is to work then a bit more working out to get a good balance between power and steam usage would be worth while doing, don't want to run out of steam half way through a lift and have to wait for the boiler to recover!!

You are making good progress.

J


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## SBWHART

Jasonb  said:
			
		

> On small engines its possible to just used drilled holes for the port face and not worry about machining slots which allows you a lot more freedom with sizes (benson is drilled as you can see )
> 
> J



That,s worth knowing 

Stew


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## Captain Jerry

Brian

Those are nice looking cylinders with a nice crisp action. I do have a comment on the valve dimensions. The inside length of the steam chest is 1.031" and the total space required for valve travel ( valve width = .657 plus total movement = .344) is 1.001. That leaves a clearance of only .015" at either end of valve travel. You risk having the corners of the valve hitting the radiused corners of the steam chest. Just a little contact may not prevent the valve from working but would likely make a "knock", even if perfectly adjusted. You can eliminate the problem by filing the inner corners of the steam chest square or by rounding the corners of the valve. This will not have any affect on the valve operation.

Jerry


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## Brian Rupnow

Jerry---Thanks for looking. I actually did have a 1/16" x 45 degree chamfer on each corner in the drawing, but after my video action, it felt like it didn't need it, so I took it off the drawing. If I hear anything knocking when the engine is all set up, I'll know it isn't opportunity and chamfer them then.----Brian


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## Brian Rupnow

My God, those crosshead guides have a beautifull shape!!! Kinda like Marilyn Monroe on steroids.---But what a pig to machine. I started with solid 1.125 cold rolled steel. The drilling, reaming, and boring are pretty straightforeward, but the removal of material from the outer diameter to yield that beautifull profile is a nasty bunch of work on my small mill. That big .625 inch diameter ball end mill I use clunks and thumps like the voice of doom. I may try to get the same result on the second crosshead using a 2 flute .625 inch endmill and plunge cutting at the ends. In the picture you can see a piece of tooling that I saved from when I built the Popcorn engine when I had to machine the crosshead for it.


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## gbritnell

Brian, 
As you have found out ball mills are not very efficient cutters as far as metal removal goes. The cutting edge is very blunt and that makes them pound against the work instead of slicing off material. Their use requires a very sturdy machine. There are several ways around this, first is to take a rotary tool, Dremel or the like, and using a small cutoff wheel or mounted stone carefully scallop the face of the ball shape back to obtain a sharper cutting edge. The second way is to use a smaller ball mill and by the process of sine/cosine step off the desired radius. Depending on the amount of stepover you use it will require a bit of hand work but I find this easier than beating away with a large ball mill. I'm really surprised that you could even use a .625 ball mill in a small mill. My larger mill would have a rough road trying to use that big of a ball mill. Another thing that you might consider when doing something like these crosshead guides is to use 12L14 steel. It's much easier to cut than 1018 or the like. 
gbritnell


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## Brian Rupnow

My last idea was NOT a good one. Making one of these crossheads with a ball end mill is miserable. Making one by plunge cutting is sheer torture, and you end up having to work from the blind slide half the time. Trust me---Don't do it that way. The results end up the same but its twice as much work. On the positive side, I now have a nice matching pair of crosshead guides. I agree with gbritnell---Large ball nosed cutters shouldn't be used on a small mill. I won't do it again.


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## Brian Rupnow

And for those of you out there who REALLY want to tie up a whole weekend machining----GO NUTS!!!


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## Brian Rupnow

Messing about a bit with the model----I added in steam pipes at 1/4" diameter. I don't think they look to big or "clunky", but beauty is in the eye of the beholder. At 3/16" they just looked too small to me. I moved the boiler a bit closer to the back of the base, and added some beefier connecting rods because of the length. When I get to the boiler, I am going to add a fire door and a pair of ash clean out doors in the base. Speaking of the base---that may be the next thing I build, so I have something to bolt all my little parts to. I find that if I don't have something substantial to bolt all my little bits to, I start to lose them.


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## Harold Lee

Coming along very nicely. Despite the difficulty you had making them, they sure look good!!!

Harold


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## Brian Rupnow

The base should be fairly straightforeward in terms of machining operations. Its going to require a lot of hogging out around the perimeter, and I haven't quite worked out whether the boiler will set in a round counterbored hole or just set on top of the base. ---Probably just set on top. I want to add on a pair of "ash cleanout" doors on the rear side between the cylinders, not sure yet of how they will be attached.


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## Captain Jerry

Brian

You are making good progress. The solid base is a good idea. Mounting the cylinders on the extended base will give you a good stable arrangement.

I have been looking at that picture of the fire door and ash doors for years and hoping for inspiration to build them since the are such a great feature to add to the otherwise bland rear view. The fire door offers a huge challenge, oval shaped and contoured to the boiler. Here is another view that shows additional detail of the fire door:






In this picture, the pipes rising vertically out of the cylinders are exhaust pipes, that rise to the top of the boiler and exhaust into the stack to aid draft. The steam pipes have completely disappeared in rust but in this picture you can see the relative diameter.






Jerry


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## Brian Rupnow

Thanks Jerry----Glad have your support, and glad you're following along.---Brian


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## Jasonb

Fire door is probably best done by squashing a suitable piece of tube and flycutting the end with a boring head to the boiler OD plus the thickness of the flange. Bend the flange to fit the boiler and then silversolder onto the curved end of the tube. Finnaly cut off excess tube, file away the flange plate inside the tube and an equal amount all round the outside then rivit to boiler.

Ash doors which look like they also serve as dampers so need a latch to hold them part way open. Can just be flat plate with two strips soldered on for the hinge lugs. The fixed part of the hinge is basically just a "U" shape drilled for the pin and filed to shape, aim for a 1/32" hinge pin.

Interesting to see the pipes better on that last photo, with the 1/4" feed it will need 3/8" exhausts to look in proportion. Also looks like a cladding sheet on the cylinders with insulation below


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## Brian Rupnow

Just in case you didn't know----Aluminum plate can be cut quite handily on a table saw with a carbide toothed blade. Its dangerous, its horribly loud, and its scary as Hell, but it beats standing around ageing waiting for my bandsaw to cut it. Thats 1" plate you see. It has a terrible habit of kicking back and trying to behead you, so you want to hang on real tight, always know where your fingers are, and don't laugh at my table saw. Its probably older than you are. I paid $25 for it 25 years ago at a yard sale and then souped it up with a 2 hp. compressor motor off a house sized propane tank storage unit.


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## Bill Gruby

Brian;

 Been cutting aluminum like that for a while. I bought a special blade just for this purpose. It's lowers the possibility of kickback,

http://www.coastaltool.com/a/freud/specialty-blades.html

 "Billy G"


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## kustomkb

> Its dangerous, its horribly loud, and its scary as Hell



Cutting freehand, that is an understatement. It is true that aluminum and wood have the same cutting speed when using carbide and I too often use the table saw for roughing out aluminum plate.

Like Bill said get a specific blade or at least one with a finer pitch.

But above all you must use a properly tuned fence and really should have a riving knife on there.

Please tell me you took the fence off for the photo.

Your parts are looking nice.


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## Captain Jerry

Brian

Not having a bandsaw, I use my tablesaw a lot. I have cut two inch some and inch and a half mostly. I use a 10" 60 tooth carbide blade and before every cut, I check the gullets between the teeth for chunks. Chunks pop out easily with a pair of needle nose pliers. When I start the blade, I give it a spritz of WD-40 and if it is going to be a long cut, I lay down a puddle of WD-40 on the cut line. I have a board clamped to the miter gauge fence and the work piece clamped to that. If cutting against the fence, I use a feather board to keep the piece tight against the fence. 

Cutting a big chunk of aluminum is no more dangerous than cutting a big chunk of oak and a lot less dangerous than cutting a big chunk of yellow pine. I have never had aluminum twist or warp as the stresses are relieved or try to clamp shut on the blade.

If you ever want to sell your table saw, I'll give you twice what you paid for it. A good, belt drive table saw beats the hell out of the new geared universal motors that you find on all but the high end saws today. ( I'm assuming that you'll throw in the 2HP motor since you won't have any need for it without a saw.

Jerry


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## Brian Rupnow

I was cutting freehand. I find that using a fence just makes the problem of kickback worse. I had a death grip on that chunk of aluminum during the entire cut process. Jerry---I was given two of those motors by someone who once worked for Superior Propane. They had a maintainance protocol that dictated changing out the motor every two years whether it had been ran or not. He had a whole damn shed full of them. I wish now that I'd got a dozen of them.


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## Brian Rupnow

So here we are, after a part days machining, with the outer profile mostly finish milled. I have one big old angle plate that I bought when I bought the mill.----It gets used only rarely, but when its needed, nothing else would work as well. Tomorrow should see most of this base finished, if my arm doesn't fall off from turning the feed handles back and forth.


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## Brian Rupnow

NUTS!!! A little checking of my endmills has shown me that I can't put that lovely fillet around the bottom lip of the base. The height of the vertical portion above the flange is 5/8", and the 3/16" ball end mill I have only has a short cutting area about 3/8" long from the very tip before it flares out to 3/8" diameter to fit the collet.


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## Captain Jerry

Come on Brian, you know the solution. You are working again. Money spent on tooling is always a good investment.

Jerry


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## Jasonb

Brian take a blunt straight cutter, long series if needs be and just grind the corners off to a small radius, I do it a lot to get internal fillets and they rip through the metal far faster than a bull nose cutter. The grinding does not have to be spot on and is easier done on a 2 flute cutter than a 4 flute. Here is one in action.


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## chuck foster

Brian, you might want to try a router bit for a nice profile in aluminum.

chuck


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## Brian Rupnow

Near as I can tell, that new 1/4" ball end cutter that I bought is going to work real slick. I got called away today right in the middle of milling my baseplate, but tonight I snuck into my shop and kind of squeezed in behind the mill to get this shot. I have never milled to an inside corner with a radius in it before. Its kind of a combination of tricks and simple math. I know the total depth of cut is going to be 5/8"-----But the radius on the ball is 1/8"----Therefore I can only cut to 1/2" depth with my 3/4" two flute cutter. Then I have to offset my cutter from the vertical wall by 1/8" and cut another 1/8" deeper. Then I put in the 1/4" ball nose tool, zero off the bottom of the cut, back up 1/8" in Z axis, wind the cutter over untill it just "kisses" the vertical wall, then start taking passes advancing the ball nosed cutter .015 at a time untill I reach my zero on the z axis. It works---but its kind of like walking a tight-rope balancing 3 plates while blindfolded. The picture doesn't show it really well, but I wasn't about to tear down my set-up to get a better picture.


----------



## Brian Rupnow

Suffered a minor catastrophe this afternoon while machining the end of the baseplate. The cutter dropped down about .100 while finishing off the flange on the end opposite the boiler. Cutter dug in, pulled down, blew the fuse in the mill!!! Not a terrible catastrophe----but a maddening one. I planned on painting the base anyways, so I filled up the almost perfect 3/4" diameter circle with J B Weld tonight and will let it set overnight with a 100 watt bulb close to it. Other than that, the baseplate is turning out quite nicely. The 1/4" ball nosed mill I purchased has put a lovely 1/8" fillet on the inside corner of the flange along both sides and across the end opposite the boiler, and I bought a peice of 1/8" square HSS to make a radius cutter where the radius blends into the curve up near the end where the cylinder mounts. I will post a picture of it when I have built it and succesfully used it.


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## Brian Rupnow

Sometimes I paint myself into corners. It is QUITE EASY to design something in 3D that looks really good, but is damn difficult to actually recreate in metal. This is one example, where the black arrow points to. After running my filleting end mill along the inside corner to create that nice "as cast" looking fillet, I had no idea how to chase that fillet around the corner. I had left the material there to fillet----Just didn't know how to go about doing it.


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## Brian Rupnow

So----I built myself a filleting too. I milled a slot into a chunk of 3/4" diameter cold rolled, 1/8" wide. I had purchased a piece of 1/8" HSS yesterday, so took it to my grinder and formed a 1/8" rad on one end. I had drilled and tapped my 'special tool' for a couple of #5-40 set screws, so that secured the HSS in the tool, then I trimmed off the other end.


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## Brian Rupnow

And "Voila!!!!!"----the results are not outstanding, but beat the Hell out of anything I could have done with a Dremel tool and a burr. I thought as I was finishing this up that I could probably have achieved the same results with my boring head if had wanted to sacrifice one of my boring tools by grinding a radius on the carbide tip. This is still going to require a bit of dressing with said Dremel tool and burr, but its been a learning experience!!!


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## Jasonb

Where there's a wil there's a way, bit of blending and a thick coat of paint and it will be looking fine. 

This is another advantage of the old cutters with teh corners rounded off they can create a larger radius though you probably would not have got a 1" cutter into your machine.

Can also be done by bolting the work to a rotary table with the centre point of the curve set to the axis of the RT and then just use the same cutter that you did the straight run with.

J


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## Brian Rupnow

Thats a world of pain mostly behind me!!! The base looks great, but it stetches my capabilities as a machinist.----But probably thats a good thing. I have some minor cosmetic work yet to do on the base, but that can wait untill final tear-down, when I paint the base.


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## Brian Rupnow

Think I'll go here next. I'm burned out from working on that base. A quickly "nested" layout shows that I can get two brackets out of a crusty old piece of brass that I have left over from some other job.





.


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## Harold Lee

Brian Rupnow  said:
			
		

> And "Voila!!!!!"----the results are not outstanding, but beat the Hell out of anything I could have done with a Dremel tool and a burr.



Brian - Good job on the radius issue. The problem is after all that work you go and cover it up with the cylinders where no one can see your handiwork. We used to have a saying that relates to that. It is like peeing in your pants in a brown suit. It gives you a warm feeling but no one notices.

Keep up the great work.

Harold


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## Brian Rupnow

*WARNING--WARNING--WARNING---I THOUGHT I HAD MENTIONED THIS AT THE BEGINNING OF MY THREAD, BUT I CAN'T FIND IT NOW.---THIS DONKEY WILL RUN ON COMPRESSED AIR, NOT STEAM. DUFFY HAS POINTED OUT THAT THE BOILER IS TOO SMALL IN RELATIONSHIP TO THE SIZE OF THE CYLINDERS----MY APOLOGIES TO ALL WHO THOUGHT THIS WAS A TRUE STEAMER--BRIAN*


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## Brian Rupnow

Slowly, Slowly Pokey Monkey----The crosshead guide supports are taking shape. I have to figure out next if its worth setting up the rotary table to round them off, or to do it freehand on my beltsander. The problem with doing them on my rotary table is that I would have to Loctite a shaft into the bores to hold them. The trouble with doing them freehand----Well we all know the trouble with that!!!


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## Brian Rupnow

I decided to take the easy way out----So I walked them out to my big vertical belt sander and freehanded them. Then a little file work, and Hey Presto!!! Now I have to set about making the wee buggers right and left hand.


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## Brian Rupnow

Cowabunga Roy----Lookit the ears on that sucker!!!! Wish that all my parts turned out so well!!!----Brian


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## firebird

Hi Brian

Very nice work :bow: :bow: :bow:

I'm enjoying this.

Cheers

Rich


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## smfr

This is coming along very nicely! Love it!  :big:


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## Brian Rupnow

Well, this should be interesting, to say the least. In right and left hand as well-----------


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## Brian Rupnow

And how does one go about making something with such wildly imaginative radii on it? Well, its like this. I needed to come up with the geometry in order to "draw" the part. Yes, even in 3D there are rules, the first of which is that you have to be able to draw the object in 2D before extruding it into the third dimension. And the geometry used in creating that drawing is composed of lines, arcs, circles, and angles, same as any mechanical drawing. 99% of the shape is purely cosmetic. The only really important geometry on the part is that the base must be flat, the top parallel to the base, and the relationship of the upper and lower bearing radii to the base and to each other. The cutout in the center, and those big swooping radii on the outer edges are flights of fancy, pure and simple. They serve no purpose, other than "eye candy". So---How will I proceed? Well, first of all, I'll print the drawing off at 1:1 scale, and glue the print of the main profile to some cereal box cardboard. Then I'll cut it out with my scissors. I will take a piece of 1/2" aluminum of sufficient size, I establish one straight edge on the aluminum plate or bar stock as my base, and set it up laying flat in my milling machine, parallel to the bed, with a piece of sacrificial aluminum underneath it. Using the hand dials (I have no electronic read-outs) I will pick up "zero" from the edge I have designated as the "bottom" and drill the two holes which appear as "half holes" on the perimeter of the frame. In the same set-up I will drill the 3 holes that form the corners of the window in the center. I will then stand the piece of aluminum on edge, with the "bottom" resting on the mill table and clamp it to an angle plate and mill the top surface to a height of 2.371" from the base. I then remove it from the mill and coat it with layout dye, and lineing my cardboard cutout up with the bottom edge and the previously drilled holes, I will trace around the cardboard with a scribing tool. I will cut the two major outer radii using my bandsaw, and the curved lines connecting the 3 "window" holes will be cut out with my sabre saw. The only important feature on the piece other than the bearing holes and the top bearing pad is the area to either side of the pinion shaft hole, which must be a straight line (not a radius) and must go exactly thru the center of the hole at the angle specified on the drawing. I will leave a bit of extra material in that area and set the piece back up in my mill to finish machining those areas. The material which is removed from the face of the plate to leave a raised "boss" at the upper mainshaft bearing will be dealt with using the milling machine and rotary table.


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## Brian Rupnow

If you have to make two plates that have identical outer contours, then what better way to start out than by bolting the two plates together, with zero clearance holes. I counterbore the material so I don't have bolt heads to contend with in subsequeunt operations. I have found that no matter how carefully I line the plates up and how tightly I clamp them before drilling, there will always end up being some minor misalignment on the two edges which are supposed to be in line, so I always take a light pass over both edges AFTER the are bolted together.


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## Brian Rupnow

Somebody is going to ask me "Why did you bolt that extra piece of plate to the edge of my bearing plates?"---Well, since I was scrounging thru my junk bin to find these two plates, they are just a tad to small. You will notice that the top "half hole" is only about 0.100 from the top edge. I can't drill a half hole---only full sized holes. And there is absolutely no way to drill a hole that close to the edge of a plate without having the drill break thru, catch and break the drill, or drill a very crooked hole. With that extra piece bolted on there, I can drill and ream my hole with no fear of that happening (part of the hole will now be in that scrap of plate). Then I unbolt the plate and throw it back into my junk bin.


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## Brian Rupnow

So there they are!!! A world of filing awaits me, but they are identical and all of the critical surfaces and holes are an exact match.


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## Brian Rupnow

The bearing stands are 75% finished. I still have a bit of light sanding to do, and some tapped holes, but I'm happy.----Brian


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## Brian Rupnow

Guess I'll go here next. I have to have some way to clamp the brg. stands to a shaft to spin it in my rotary table chuck, and this is probably the best way---seeing as I have to build them anyways.


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## Brian Rupnow

I'm getting better at this radius business. I have to tap some holes for the pinion shaft bearing caps and to hold the stands to the base, and they're done. Once I get the bearing stands finished, I can either flip or flop.---That is---Move to the gears and winch drum and clutch, or finish of the engines and get them running.---Not sure which yet.


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## Brian Rupnow

And for tonights enjoyment and entertainment (after 8 hours at one of my "real" jobs)----A potload of tapped holes and a nifty set of pinion bearing caps!!!


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## Brian Rupnow

I've been thinking of what to do next, and have decided that since the success or failure of the entire project depends on the engine, that is where I should go next. This is a relatively simple twin cylinder self starting engine, with what amounts to an EXTREMELY long center section to the crankshaft. Over the next few weeks I will be concentrating on finishing and running the engine before moving on to the winch. I'm undecided as to whether or not this winch should have a brake. There is no room for a brake at the end where the clutch is, but at the other end of the winch drum, if I remove the flange and replace it with a disc of cast iron, then a band brake can run on the outer surface of the disc. Obviously, the clutch and brake should both be operated from the same side of the engine, so that means there would be some kind of cross rod running through the base from side to side so that both levers can be operated by one man from one side. On one hand, this adds a fair bit of complexity to the build, but on the other, since I made this a single drum donkey I have saved myself a lot of work, so it kind of balances out. What is your opinion fellows?----Brian


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## Captain Jerry

Brian

From what I have seen, it was done both ways. On smaller units, the clutch and brake were at the same end of the winch with the clutch expanding internally and the brake wrapped externally on the same drum. On larger hoists, the clutch and brake were at opposite ends to prevent heat from one function causing slipping on the other. You can do it either way and still be right. But I don't think I have ever seen a hoist without some kind of brake or pawl.

I doubt that a hoist or donkey was ever designed or built with a solid base casting like yours so passing a brake actuator rod through a fabricated base frame would not be a problem. You could easily pass a rod through the solid base but the brake mechanism has to be inside the bearing stands. How about running the rod through a couple of pillow blocks on the top surface of the base?

Jerry


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## Brian Rupnow

Think this is where I'll expend my efforts today. These flywheels are smaller in diameter than I am accustomed to. I know for a fact that a double acting twin cylinder engine with the crank throws 90 degrees out of phase will run with no flywheel at all, but its pretty "Hirky Jirky". I have made these flywheels as thick as I can without compromising the look of the donkey.


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## cfellows

It's looking nice, Brian. 

Chuck


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## Brian Rupnow

Chuck---Thanks for dropping in and saying Hi.-----Brian


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## Brian Rupnow

And this is what I spent the day at!!! The pictures are somewhat "posed" with a piece of 1/4" cold rolled holding them up. I am happy with what I've done today, but consider----Its 4:30 now and I started these this morning at 8:30 !---No wait, thats a lie----I spent a couple of hours at least tapping the base for the bolts from underneath that hold the bearing stands in place, and the threaded holes in the sides of the base that hold up the brass crosshead guide supports. Still, darned expensive flywheels if I had to pay somebody to make them. Last week I bought a set of small broaches at BusyBee tools and this might be my first opportunity to broach something.


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## Captain Jerry

Brian

You don't need to overdo the crank thickness. Because the winch gear is always engaged, it's rotational energy is added to the crank web. The problem is having room for the crank web between the con rod and the eccentric strap. Plus there is precious little room between the crank web/flywheel and the bearing stands for the eccentric.

Jerry


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## Brian Rupnow

Jerry---I assume you meant the flywheel thickness. You are absolutely right!!! There is such a lack of room between the flywheel and the bearing stand that I have changed the design of the elliptical cam to be a hubless style. That is what let me gain enough room to fatten up my flywheels a bit.


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## Brian Rupnow

I've been looking at the pictures posted above, feeling that something just didn't look right. It just hit me---when I had the engines off this morning to drill and tap the base, I swapped sides unknowingly when I reassembled it. The valve bodies are supposed to set inboard, not outboard. No grief---I just switched then back to being in the right place.


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## Brian Rupnow

I'm going to try a BIG STRETCH now and do something I have never done before. As I said earlier, I purchased a small broaching set from Busybee tools, and a big arbour press, and I guess the time has come to try it out. I didn't want a hole through the face nor the side of my brautiful flywheels, but a little sneaky cad work tells me that if I go in through one of the windows at 26 degrees I can get a tapped hole directly over the key. Wish me luck.---Brian


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## b.lindsey

Itsi all still looking great Brian. The broaching shouldn't present any problem. Is the window for the 26 degree set screw hole large enough to let a center drill in there so you can keep the drill on the correct angle? Keep up the amazing progress 

Bill


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## Brian Rupnow

Well there!!! I've broached my first two keyways.---and as Bill Lindsay said, Its "Easy -Peasy"!!! (Well, Bill didn't actually put it that way, but he was right, its easy.) However----As in all things there apear to be a couple of caveats that I was unaware of. I used lots of cutting oil and ran the broach thru the first flywheel on the left, was thrilled with how easy it was. and took everything apart. But wait----the keyway was way to shallow. Okay, from what reading I have done to bone up for this test, thats why there is a spacer included in the kit. So---I put the spacer back in and ran the broach through again. Great!!! Now the damn keyway is too deep!!! Now I'm starting to feel a bit like Goldylocks.---(Ref the 3 bears.) On the next flywheel (on the right) I ran the broach through once, then put in the spacer, then ran the broach half way through the second time.---Now thats what a keyway is supposed to look like. i'll remember this for the next time I broach something.------And no Bill, I didn't have a center drill small enough to get in there and start the holes. I did however have a long, 2 flute, 1/16" diameter end mill that did the job quite nicely.


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## Brian Rupnow

Whats the best way to but a 1/16" keyseat in a shaft? If I use a 1/16" endmill, it always cuts a bit wider than 1/16". If I use a 1/32" endmill, I break it. How about those woodruff key type cutters 1/16" wide---just run it out at the end of the shaft instead of cutting a true woodruff pocket?


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## cfellows

Brian Rupnow  said:
			
		

> Whats the best way to but a 1/16" keyseat in a shaft? If I use a 1/16" endmill, it always cuts a bit wider than 1/16". If I use a 1/32" endmill, I break it. How about those woodruff key type cutters 1/16" wide---just run it out at the end of the shaft instead of cutting a true woodruff pocket?



Brian, that would probably work just fine. On the other hand, why don't you just use a woodruff key?

Chuck


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## Brian Rupnow

Good plan chuck.---I hadn't thought of that.


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## Brian Rupnow

I've spent the afternoon in the continuing education of Brian. First---Nobody in the world (at least the part accessable to me) carries nor can get 1/16" square keystock!!! However, they can get 3/32" square keystock overnight. Secondly---BusyBee tools doesn't carry 3/32" woodruff key cutters---(They didn't even seem to know that there is such a size). Thirdly, Brafasco tells me that there is no source for 1/4" x 1/4" shoulder bolts (For where my con-rod attaches to the flywheel) and that they would be special order and would cost $26 each. Fastenal tells me that they cost $2.18 and can be brought in for tomorrow. Barrie Welding tells me that 3/4" diameter brass will cost $4 for 4", but only if I can find a "short" in the rack. If somebody has to cut 4" off for me then it will cost $8.00. The guy who can get me 3/32" keystock overnight can also get me a 3/32" woodruff key cutter overnight. Thirdly, the broach bushing that fits my 1/4" bore in the flywheels will also accept the 3/32" broach.---thats a good thing!!!! I've learned a great deal this afternoon!!!!


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## tel

Why not cut the key from the edge of a bit of 1/16" sheet? That's what I do - up to 1/8" or so. In that size there is no need for hardened stuff.


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## Brian Rupnow

Not a bad plan Tel. These are just "first time" pains. Once I get a foot of 3/32 square in here (Its only about $10 for a foot) that will be enough to last me for years. Same deal with the cutters.----Brian


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## Brian Rupnow

Yesterday during all the hoo-haw about shaft keys, I did manage to actually make some parts. I designed, built and installed a pair of pinion shaft bushings and got a good start on the crossheads.---A note about those bushings.---You will notice that the o.d. is about .005 undersize from the holes for them in the bearing stands and caps which call for .312 reamed holes. I did this on purpose, because the bearing stands set so far apart that there is no way to ream them both in one set up. I can completely dismantle my pinion shaft from the flywheels and pinion gear and slide it out thru the bushings without ever actually removing the bearing caps. So---a light came on. Pull off the bearing caps, slide the bushings over the shaft, lay in a bed of "liquid metal epoxy" where the bushings set, and bolt everything back together with bushings and shaft in place and leave overnight. This morning the shaft turns freely in perfect alignment with no binding in the bushings.


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## Brian Rupnow

Making itsy bitsy pieces this morning. Not very exciting, but definitly needed for the engine to run. Pictures are already posted of Donkey crosshead and Donkey connector pin.


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## Brian Rupnow

I'm far enough advanced at this stage to build a pair of connecting rods.


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## Brian Rupnow

Man, this is really starting to get exciting now!!! I lapped the crosshead into the crosshead tube today with 350 lapping compound and put a retaining bolt through the top of the brass crosshead support loop into a tapped hole in the end of the crosshead tube to keep everything positioned properly. I made the connecting rods up this afternoon from a piece of 1/4" brass bar. They are not finished yet, I still have to relieve both sides down to a 3/16" total width except at the end where they attach to the flywheel. I just had to dummy things up to see what it would look like assembled. I love it when I get to this stage and things finally start to look like the finished model!!!


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## Brian Rupnow

This morning I had a lesson---"All about Keyways"!!! I had read that you can not mill a keyway for a given size of key with the same size of end mill. Not always believing everything I hear, I had to try this and see. So---First up was a keyseat milled with a 3/32" two flute carbide endmill. Guess what?? Everybody was right. 3/32" as a decimal is 0.09375" The slot the cutter made is .104" wide. The key fits---SURPRISE-- SLOPPILY.


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## Brian Rupnow

Next up was a keyseat cut with a 3/32" woodruff key cutter. The 1/8" pin you see sticking out sideways was not in there while I was making the keyseat cut. It is my "horizontal reference" for when I have to rotate the shaft 90 degrees to put the keyseat in the other end---Remember, the two cylinders will be 90 degrees out of phase to make the engine self starting, and I need to be able to find that 90 degrees when I cut the keyseat in the other end of the shaft. Again, everone was right . This keyseat turned out to be exactly 0.094" wide. Only problem was, I screwed up my height calculation and the keyway was not on the center of the shaft.


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## SBWHART

You make the key fit the slot 

Stew


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## Brian Rupnow

Moving right along----Of course every shaft has two ends, so we went to the other end and repeated a cut with the woodruff style cutter.---And BINGO!!! Everything was dead nuts like it was supposed to be!!! One caveat-----When you do this have only enough shaft stuck out past the end of the vice to clear your cutter. Small shafts like this one will deflect away from the cutter a lot if it can.


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## Brian Rupnow

Now, if you have lived a good clean life (As I always do) your end result should look somewhat akin to this!!!


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## Brian Rupnow

That should be enough for today. Keyways are cut and keys installed. Both crossheads are lapped into their respective tubes, and both con rods are installed. The engines turn over by finger presure on the flywheels, but its getting stiffer as more and more pieces go together. One thing about it, when you get to this stage of the build and everything revolves completely, at least you are assured that you haven't muffed a dimension and that a piston is trying to bash its way out through a cylinder head at one end or the other. This coming week I hope to build the elliptical cams and associated linkage to operate the valves.


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## vcutajar

Brian

I've been following this thread for a while now. Your engine build is moving along quite well but I really enjoy the way you explain how you go about doing things in detail. Keep it up.

Vince


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## Brian Rupnow

Thanks vince. When I first started machining things 3 years ago, I seen such wonderful things on this forum, but on many of them I was left thinking "Oh my God, how did they do that? I am far from being an expert at this stuff, but I am good at documentation and technical write ups. I hope that what I'm doing will give some of the less experienced out there enough knowledge/courage to try some of this stuff on their own. Just one thing----I have a bad habit of using my milling cutters mounted in the chuck. Don't do that. Its hard on the bearings in the head of the mill.


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## chuck foster

hey brian, model is looking good are you coming to cookstown show this summer............sure would like to see some of your models.

take care

chuck


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## Brian Rupnow

Chuck---Thats a good question. I have so many new models now that no one except the guys on this forum have ever seen. i might come down, but they would have to rent a compressor to run all of my stuff alone.----Brian


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## chuck foster

i am sure a compressor could be arranged if you like .......... i can talk to my friend ed, he has a bunch of gas engine models there every year and he is kind of in charge of the model stuff.

i look forward to seeing you and your models, and this year i will be bringing some of my models.

chuck


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## Brian Rupnow

I'm going to "borow" a trick I seen Stew Hart do the other day on the engine he is currently building. I have always made my eccentric straps in two pieces and then fiddled them together after the fact. Stew makes them as one piece but leaves the center section a bit longer than necessary---just the width of a slitting saw blade. Once they are slit, the pieces fit exactly together and can then be bolted together and bored.


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## Brian Rupnow

Here we are taking the big slice-----


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## Brian Rupnow

And here's how it ended up. I may do a bit of cosmetic filing here or there, but all in all it went well. Also in the picture you can see one of the hubless cams. In my original design these cams had hubs on them, but there is so little room between the flywheels and the bearing stands that I eliminated the hubs just to give myself some room. These cams work just as well as the hub style, its just that they are a real bugger to adjust the valve timing on. You have to remove the "cap" side of the eccentric strap to get at the set screw in the center of the hubless cam to adjust it rotationally. Please note that I have removed the eccentric strap drawing which I had posted much earlier in this thread, as it has undergone some fairly dramatic changes. I will post a new drawing tomorrow.


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## Brian Rupnow

This is a detail of the hubless cam. A picture is worth a thousand words----


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## Captain Jerry

Brian

When I have used hubless eccentrics in the past, I have drilled a hole through the cap big enough to pass the hex wrench that adjusts the set screw. Then you can loosen the set screw, move the crnkshaft and retighten without taking it apart. Much easier.

Jerry


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## Brian Rupnow

And these my friends, approach the threshhold of what I can see and work with. They are also the last of the engine parts except for the bent valve control rod which is a peice (well, 2 pieces) of bent 1/8" round cold rolled with a #5-40 thread on each end. Cross your fingers for me. We may have a runner by tomorrow!!!!


----------



## SBWHART

Brian Rupnow  said:
			
		

> And here's how it ended up. I may do a bit of cosmetic filing here or there, but all in all it went well. Also in the picture you can see one of the hubless cams. In my original design these cams had hubs on them, but there is so little room between the flywheels and the bearing stands that I eliminated the hubs just to give myself some room. These cams work just as well as the hub style, its just that they are a real bugger to adjust the valve timing on. You have to remove the "cap" side of the eccentric strap to get at the set screw in the center of the hubless cam to adjust it rotationally. Please note that I have removed the eccentric strap drawing which I had posted much earlier in this thread, as it has undergone some fairly dramatic changes. I will post a new drawing tomorrow.



Another little trick is to drill and tap before you split, that way they bolt back together exact.

Comming together well Brian it will soon be a runner.

Stew


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## tel

And I do 'em slightly differently again - bolt two bits of material together as the first stage, before any whittlin' begins.


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## Brian Rupnow

I must have lived right this week!!! ;D ;D ;D I timed the engine statically, disconnected the far side connecting rod, and plugged in the air.---And away it went!!! Its running on about 10 PSI which is the lowest I have ever had a brand new engine run with no break in whatsoever. Tomorrow, if I have as good luck with the far side cylinder hooked up, I'm golden!!!


----------



## smfr

Whoohoo! Nice one! :big:


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## SBWHART

Nice one th_wav

Stew


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## Harold Lee

Great Job Brian!!!!!! It sure look like a good runner. I'll bet when the other cylinder is hooked up it will run like a finely tuned Rolls Royce.
Keep em coming!

Harold


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## Captain Jerry

Hooray! Half a runner!

Its funny that we both come to the same operation (eccentric straps) at about the same time from different directions. Not surprisingly, I do it a bit differently. I drill and tap the solid bar before splitting with a saw. The American Hoist donkey has a slightly different set up but it is very tight in there. In fact on the Amhoist design, the eccentrics do not even have flanges which saves just a bit of room.

Jerry


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## cfellows

Nice, Brian! Isn't it great to realize that we are getting better and better with our projects.


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## Brian Rupnow

And this is the very last part that had to be made as far as the engines were concerned.


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## Brian Rupnow

This is what I've been looking foreward to for the last week!!! The engines run real sweet together, and self start easily at any point in the rotation. The second cylinder had a few more tight spots in the crosshead tube, but after a bit of work with 320 grit lapping compound it loosened up. As soon as it loosened up, I ran it in using the other operating cylinder for power for an hour. Its sitting on the floor in my office as I type this, ticking away on about 10 PSI air pressure running on both cylinders. I hope to take a bit of a break now, and then start on the rest of it---winch assembly and faux boiler. I simply had to assure myself that the engines were going to run all right before I invested a lot of time in the rest of it. Thanks for watching guys, and stay tuned-----There is a lot more yet to come.---Brian


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## cfellows

Sweet! Looks and runs great.

Chuck


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## Brian Rupnow

Thanks for the nice compliment Chuck. It certainly is amazing how quickly one improves when you are really interested in what you are doing.


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## steamer

Looks great Brian!  Can't wait to see it all meshing and pulling!


Dave


----------



## vcutajar

Congrats Brian. Smooth runner.

Vince


----------



## SBWHART

Well done Brian its got a real nice beat.

 :bow: :bow: :bow:

Stew


----------



## Brian Rupnow

I went downtown, did a bit of business, and got my spring haircut. (Hopefully that will hurry spring along!!!) I stopped in at my aluminum supplier and priced out 4" aluminum tube and 4" aluminum solid round. After I picked myself up off the floor I hurried home and looked in my "big scrap" cupboard.--And darned if I didn't find the perfect boiler in there!!! Of course, it doesn't look much like a boiler right now, but give me 20 minutes-----


----------



## bronson

Looking really good Brian runs great and sounds good nice work as always.

Bronson


----------



## Brian Rupnow

Ha!!!!! I knew there was a boiler in there!! Now all I need is a piece of aluminum to make a transition cone. It did take longer than 20 minutes, but then again, it was FREE. It stretches the capacity of my 10 x 18 lathe to work on a 4" pipe, so I may take it to one of the machine shops I do work for and have then do a quick bore to reduce the wall thickness a bit. Since this only has to look like a boiler, and will ultimately be painted flat black, I think this will do just fine.


----------



## Captain Jerry

Brian

Are you planning to get the cone out of solid stock on the lathe or are you going to roll it from sheet stock? Sheet would be in keeping with full size practice since it is mostly a weather shroud and is not part of the pressure vessel.

Jerry


----------



## Brian Rupnow

I'm going to whittle it from solid Jerry. I don't have any slip rolls, and having done a lot of automotive paint and bodywork over the years, I don't want to expend the effort to make a sheet metal part look "right".


----------



## zeeprogrammer

Just finished reading through the thread and it was very enjoyable.
I got interested in this kind of engine from Jerry's thread and am looking forward to seeing more.


----------



## Harold Lee

Great job on the engine Brian. It looks and sounds like a sweet runner. You might want to go back and re edit your video and take out the part where you state you are going to take a bit of a break since you immediately started work on the boiler. :big: :big: ;D Everyone of us can relate.... Why do those projects in the shop keep calling our names when we have so many other things to do?

Keep up the good work!!

Harold


----------



## Brian Rupnow

Hi zee---Glad you dropped by to say Hi.----Harold--I did take a break. I went and got a haircut!!! ;D ;D


----------



## Brian Rupnow

Here we have a $30 lump of aluminum, 4" dia. x 4" long. Over the next 8 hours, during the impending blizzard and freezing rain, I am going to do my best to turn it into a beautifull transition piece for my faux donkey boiler. I have my auxiliary heater turned to HI, I have an oldies station on playing good rock and roll, and my good wife is off working earning some grocery money. Does it get any sweeter?


----------



## maverick

Brian,
 The only thing that makes it any sweeter is realizing how sweet it is.
 Wonderful build by the way.

 Regards,
 Maverick


----------



## cfellows

Brian Rupnow  said:
			
		

> Here we have a $30 lump of aluminum, 4" dia. x 4" long. Over the next 8 hours, during the impending blizzard and freezing rain, I am going to do my best to turn it into a beautifull transition piece for my faux donkey boiler. I have my auxiliary heater turned to HI, I have an oldies station on playing good rock and roll, and my good wife is off working earning some grocery money. Does it get any sweeter?
> 
> (Image deleted)



Aaahhh, life is good...

Chuck


----------



## gbritnell

Hi Brian,
Being as the boiler wont' be boiling water would it have been more cost effective, and lighter, to buy a piece of aluminum tubing. Speedy metals has 4.00 dia. x 4.00 for $3.80. 
gbritnell


----------



## Brian Rupnow

gbritnell  said:
			
		

> Hi Brian,
> Being as the boiler wont' be boiling water would it have been more cost effective, and lighter, to buy a piece of aluminum tubing. Speedy metals has 4.00 dia. x 4.00 for $3.80.
> gbritnell


And pray tell, my friend---How do I turn that into a transition cone?


----------



## tel

Better still, roll one from sheet - same way as a real one.


----------



## JorgensenSteam

Cast that puppy.


----------



## fcheslop

Spin it :big: Nice build really enjoying following its progress
best wishes Frazer


----------



## Brian Rupnow

We start this grand foofaraw by using a center finding square to locate the approximate center on one side and putting in a hole with the largest countersink tool I have. When this thing goes up in the chuck, the chuck is holding on with the "Tips of its fingers" and I don't want this coming out of the lathe at speed and hitting me!!!


----------



## Brian Rupnow

Here we have a semi finished transition cone. It still has to have a step machined into the large end to fit snugly into the 4" pipe I machined yesterday. As you can see, my plan changed mid-stream (as often happens) and I decided not to use the smaller "smokestack" pipe, but instead machined it right onto the end of the cone.


----------



## Brian Rupnow

And all morning I've been expecting the Beach Boys (or whoever sang it) to pop up behind me and start singing "Goin' to Swarf City'!!!!


----------



## tel

;D Yup - there's $29.35 of your $30 piece right there!


----------



## bearcar1

Man, that is certainly one expensive boiler top.

BC1
Jim


----------



## RonGinger

Thats not much of a swarf pile. How about this one 
	

	
	
		
		

		
		
	


	




That was the most miserable pile to clean up we ever had- it was springy, long, just a mess.


----------



## Brian Rupnow

Ron---Your swarf pile is bigger than my shop!!!


----------



## Brian Rupnow

The boiler top is finished. It cost me $30 and a day in my shop. I think its beautiful. There is NO other way to do a transition top like that from raw material to "ready for paint" in one day. I know---I did bodywork and paint for about 5 years, and although you can make something like a boiler top very lovely you absolutely can not do it in a day. If making from sheet metal-----first you lay it out---then assuming you have a set of slip rolls and know how to use them you roll a cone. If the cone comes out the right size the first time (A rare event) then you have to weld it or rivet it to join the ends. Then you prime it---2 or 3 times. Then you spot putty all the divots that show up when its primed. Then you wait for the spot putty to dry---then you sand the spot putty and prime it again----and so on ad infinitum. I know. I've lived it. What I've done today seems like a lot of work, and yes, it used up a day. but all it needs now is some epoxy to hold it in place and a shot of flat black enamel.


----------



## Love4Steam

Brian,

I am building a Bill Harris steam roller. I have the enging mosly completed and am looking for boiler fittings. It appears your boiler is only cosmetic, but have you found scale boiler fittings for any other projects?

I have found several vendors such as PM research, but have not found a scale safety valve or boiler check valve to work on 100 psi.

Any suggestions?

Doug


----------



## Brian Rupnow

Sorry Doug----Can't help you there. I just found out about PM Research last week.---Brian


----------



## Love4Steam

Here is another good sorce for model parts http://www.americanmodeleng.com/

And one more, but I have had some bad experience with them lately http://www.colespowermodels.com/index.html

I am a live steam hobbist. Check out http://www.discoverlivesteam.com/

Nice work on the donkey. I will post some photos of my steam roller soon.


----------



## Jasonb

What scale is Harris's roller? You should be able to make your own fittings, I've done it for the 1/12 engine in my avitar and the current 1/6th one.

J


----------



## tel

1:8 (1 1/2" scale) Finding fitting should not be difficult at all, even easier to make 'em - and anyone who can build the Bill Harris Donkey is well and truly capable of making a few fittings. 

I'm very tempted to do one myself - it is a great design.


----------



## tel

> There is NO other way to do a transition top like that from raw material to "ready for paint" in one day.



I dunno Brian, I've made quite a few truncated cones - mainly for reducers in dust extraction lines and I would figure on 2 1/2 - 3 hours top.


----------



## steamer

Plus 1 for American Model engineering Supply!

Dave


----------



## Brian Rupnow

The following 3D models are intended to give a bit of insight as to how the boiler connects to the base and how my airlines will be run. I am kind of making this up as I go along, and since I have to create these 3D models anyways to clarify it for myself, I thought you might want to see. Since the main boiler tube is made of steel, I can weld a piece of 1" x 1/2" flatbar across the bottom inside and put two 1/4" clearance holes through it. These can be used to bolt the boiler to the baseplate. I want the transition cap on the boiler to be removeable, but I don't want somebody to steal it at a show--so---I have welded a piece of 3/4" rod to that crossbar at the bottom of the boiler tube and tapped the top of it 3/8"-16 unc. A stepped bore in the transition cone lets me put a washer down the top that stops at the register (step) and allows a 3/8" bolt to secure the transition cone to the boiler tube. That way I can remove it with a wrench, but grabby fingers can't pocket it and walk away with it. Since this model will run on air and not steam, I have drilled the base for my air inlet just below one of the cylinders and it surfaces inside the boiler tube. The bent tubes which run from the top of the boiler tube down to the cylinders will be connected with a Teed flex line to the air spigot which surfaces inside the boiler. I still haven't totally worked these air tubes to the cylinders out, but since brass is so difficult to bent I am considering making the lines from steel automotive brakeline, which can be bent in quite a tight radius without kinking. I will add a cosmetic fire door and ash cleanouts to the boiler and base as this develops farther.---Brian


----------



## Captain Jerry

Brian

By bolting your boiler to the base like that you will spoil its use as a cocktail shaker! What a shame.

On a less serious point, since you are planning piping from the boiler to the cylinders, where will you put the throttle valve? In full size practice, the steam line passes through a throttle valve within reach of the operating engineer and is then through a tee to the two cylinders. Unlike a mill engine, which runs all day at a constant speed, these things are started, stopped and throttled up and down frequently.

Jerry


----------



## Brian Rupnow

Jerry--I hadn't thought of that. Thanks for bringing it to my attention. i will have to rethink the plumbing line positions.---Brian


----------



## Jasonb

Brian I thought you were going to use the scale pipe elbows, tees etc as you mentioned them early on in this thread. PM Research do them to suit your 1/4 pipe. Plus everything can be taken apart if its threaded.

As well as the throttle you may want to add a means of lubrication as well unless you lube teh main air supply anyway.

J


----------



## Brian Rupnow

There!!! Nobodys going to rip off my smokestack unless they are carrying the appropriate Allen wrench.---This is a view "down the stack" as well as a very out of focus shot of the strap welded across the bottom inside of the boiler, and a view down the boiler without the cone in place.


----------



## steamboatmodel

Brian what type of base are you going to mount this on? One of our members mounts all his engines on wood bases which contain a small Filter Regulator and Lubricator (Air Tool Oil) unit. Can I talk you into bringing It down to one of our meetings in Toronto when its finished?
Regards,
Gerald.


----------



## Brian Rupnow

Steamboatmodel---I don't ususally mount them on any kind of base. The base of that model "as is" is a piece of 7/8" solid aluminum. I can't imagine it requiring any other kind of base. I would love to bring it to Toronto and show it when its finished.---Brian


----------



## Brian Rupnow

Captain Jerry---Do you have any pictures of one of these control valves?---I don't know if the unit you have access to still has the control on it or not.----Brian


----------



## Brian Rupnow

tel  said:
			
		

> I dunno Brian, I've made quite a few truncated cones - mainly for reducers in dust extraction lines and I would figure on 2 1/2 - 3 hours top.


Tel---You're a better man than me!!! I'm not saying you couldn't do it in 8 hours, but I KNOW that I couldn't.---Brian


----------



## Brian Rupnow

This is a request for help----. I have dug through the literature I have amassed on steam donkey engines, and think I have found the control valve which Captain Jerry was referring to. Its a manual control valve which looks a lot to me like it would be a form of ball valve in the main steam line before it branches off to the two cylinders. Now--It seems to me that I seen somebody post plans on this forum for making a similar simple valve, but I can't remember who nor when. If someone can direct me to that post, I would appreciate it. I would design one myself, but I see problems with it constantly leaking air around the shaft that operates the ball. That shaft can be blind on one side, but it must exit through the housing to mount the handle, so I assume it would require some form of gland.-----Brian


----------



## Captain Jerry

Brian

The control valve of the AmHoist Donkey on the docks in Brunswick is long gone. What does remain, although unattached to anything is the control handle. I t took me quite a while to understand what it was because it is just jammed down behind the boiler not attached to anything. There are two handles that look like hand cranks for a Model "T" Ford. They are atached by 50 years of accumulated rust to a common shaft that reaches from the valve at the rear of the boiler to the operators position between the two drums and is supported horizontally by some brackets. The two handles would let the operator control the engine from a position at either drum. I have some pictures that I will look for and post.

In the AmHoist Brochure there is a picture of the actual valve which is very cool. I am considering trying to build one like it for my project. I looks much like a "D" slide valve but much simpler because there is no exhaust but the valve face is flat and a sliding block covers and uncovers the port. When the valve is closed, steam presure holds the slide face against the port face to help seal. There is no description of the gland.

Jerry


----------



## Brian Rupnow

Thanks Jerry. For the sake of visual comparison, that is a 1/4" NPT ball valve laying on the Donkey, and its comparitively huge. Its as big as one of the cylinders!!!


----------



## gbritnell

Hi Brian,
Why does it need to be a 'ball' valve? By that I mean you could make a cylindrical valve just like the ones used one the model airplane carburetors. You make the body of the valve with the shape that you like. You bore blind hole in it. You then fit a cylindrical piece with a stem on it for the handle attachment. This could have .0002 clearance, just enough for it to turn smoothly. This cylindrical piece would have a cross drilled hole in it for the valve action. All you would have to do is make up a cover plate to hold it in place. With a very small clearance you should get virtually no leakage passed the valve and out the stem. 
gbritnell


----------



## Captain Jerry

Brian

Here is the picture with the two control handles on the shaft. The correct position of the shaft is parallel to the cylinder rod, 4 or 5 feet above it.






Jerry


----------



## Brian Rupnow

Thanks for the picture Jerry. George---Yes you are right, I've been thinking along the same lines. almost impossible to turn a ball that small to the required accuracy, but a cylinder is fairly easy stuff. Maybe I'll design and build one.---Brian


----------



## Jasonb

Brian have a look at Ramons table engine thread he has a valve on that. Rather than a ball valve you will find it easier to use a tapered cone much like a cylinder drain cock, they will be self sealing and good for a a couple hundred psi.

http://www.homemodelenginemachinist.com/index.php?topic=16453.msg175170#msg175170

If there is not enough detail on Ramons thread then let me know and I'll give you drawins of either of these two which can be adapted
http://img.photobucket.com/albums/v156/jasonballamy/Engineering/PICT0343.jpg
http://img.photobucket.com/albums/v156/jasonballamy/Fowler A7/PICT0147.jpg

The Valve that Jerry describes is commonly used on traction engines to regulate steam from boiler to valve chest. Its just a loose puck like a slide valve that is held to teh face by steam/air pressure and as it slides back the port is opened

J


----------



## SBWHART

Brain

I made a steam valve for my over crank:- drawing attached

Stew 

View attachment Main Valve-Model.pdf


----------



## Jasonb

Stew I don't think a screw down type will work, you need a quick 90 deg on/off action that works with a lever much like cylinder drain cocks


----------



## steamer

Hey Brian,

If its only to throttle with, use a butterfly valve. they are very effective for throttling and are very low force for actuation.

They are also something that can be machined on a lathe in the home shop.

Dave


----------



## Brian Rupnow

Thank you for all the great responses gentlemen. I thought on this issue last night and decided to design and build my own as per GBritnells suggestion. I have started a seperate thread on the valve over here--
http://www.homemodelenginemachinist.com/index.php?topic=17809.msg183704;topicseen#new


----------



## Brian Rupnow

Okay Jerry----Now I can answer your question. This is the valve that will hopefully control the speed of the Donkey engines
 Airtight as a ducks butt!!! The o-ring may have been a bit of overkill, but it certainly doesn't leak around the valve stem. Doesn't SEEM to leak through the valve either, near as I can tell. I'm going to revise and repost the main body, as I only made the counterbore that the o-ring sets in 0.040" deep. As a consequence, when you squash a 0.62" cross section o-ring into a 0.040 space, it squabs out too much and makes the valve stem stiff to turn. By the way, that o-ring is a number 010 from Hercules o-rings. It is purported to be 1/4" inside diameter x 0.070" in cross section, although when I measured it with my vernier I only read it to be .062" which is exactly 1/16".


----------



## cfellows

Okay, Brian, I know it's too late now for this suggestion, but, I'll offer it anyhow. I've found for air control, I get a lot finer adjustment with a needle valve.

Chuck


----------



## Brian Rupnow

You're probably right Chuck, but the pictures I had suggested the type of valve I designed. I just can't imagine somebody trying to use one of these original Donkeys for a hoisting or logging operation and screwing a needle valve in and out. ;D ;D ;D Normally, I don't have any kind of control valve on my engines, I just plug in the air supply from my regulator and govern the speed with the regulator. This Donkey however is a bit of a different beast. For one, it is self starting. I have been asked to exhibit this engine, and it always shows a bit better if you can at least turn the air on and off with a valve/lever that was actually used on the original machinery. I don't really know whether or not I will actually be able to adjust the speed of the engine with this type of valve, but at least I should be able to turn the engine on and off with it. The only other time I made a valve similar to this one was on the carburetor of one of my gas engines, trying to use it as a throttle.---It didn't work worth a darn, seemed to either want to run wide open or not run at all.


----------



## Brian Rupnow

sbwhart  said:
			
		

> Brain
> 
> I made a steam valve for my over crank:- drawing attached
> 
> Stew



Stew---Thank you. That is the one I was remembering but couldn't find. I will use the one I just made, but it may yield more use as an on/off valve than actually be usefull for any speed adjustment. I simply don't know.


----------



## Captain Jerry

Now you're cooking. That should do the trick. I don't think fine control is need. You need to be able to go from full stop to full go in one easy motion. Your design looks right in both character and scale but if you had to use it 10 or 15 times an hour, you might appreciate a more comfortable handle. I think you will all the speed control that you want. You can increase the sensitivity by increasing the length of the handle.

Jerry


----------



## Maryak

Brian,

Almost without exception these engines were controlled by a throttle and a Differential Valve to reverse the direction of rotation. The engines were also full admission with no lap or lead.

I hope this is what you are looking for.







Best Regards
Bob


----------



## steamer

Wot Bob said.!

The valveing on the tug winch I got into was very similar to what bob has posted...and yes full admission/ full stroke.

Dave


----------



## Captain Jerry

Bob

that is a very interesting valve arrangement but I don't think it has anything to do with the donkey style winch that Brian is building. It appears to be two cylinders in a common block, separated by spool valves and an integrated control valve. That might be what you find in a shipboard winch but on this type of machine, the cylinders are about 4' apart and reversing was not common at all. If reversing was supplied, it used Stephenson or Gooch linkage.

I don't think you can reverse a D-slide valve engine by swapping the inlet and outlet, can you?

Jerry


----------



## Brian Rupnow

Gentlemen---In regards to whether or not a small valve like I built yesterday will serve to adequately control my twin cylinder donkey engine.--Please look at the attached vido.


----------



## steamer

Hi Brian,

I don't have any issue with a ball valve as a throttle...I use one on my steam launch!  Works very well there.






Steam winches typically had full cut off.....that was my point

Whether a donkey had full cut off or not....well....guess I can't really say.

Glad it's working out for you!

Dave


----------



## Brian Rupnow

Just ordered up all my fittings and 3 foot of pipe from PM Research. I found a post on here the other day about making up jigs to machine the cast brass fittings. Now I'm going to have to hunt it up again!!!


----------



## Captain Jerry

Good show! I never had a doubt.

Jerry


----------



## Harold Lee

steamer  said:
			
		

> Hi Brian,
> 
> I don't have any issue with a ball valve as a throttle...I use one on my steam launch! Works very well there.
> 
> 
> 
> 
> 
> 
> Steam winches typically had full cut off.....that was my point
> 
> Whether a donkey had full cut off or not....well....guess I can't really say.
> 
> Glad it's working out for you!
> 
> Dave



Come on Dave.... After the teaser of the backhead of your boiler, show us some more of it!!! 

Harold


----------



## Maryak

Captain Jerry  said:
			
		

> I don't think you can reverse a D-slide valve engine by swapping the inlet and outlet, can you?
> 
> Jerry



Whilst not common, in full size practice, actually yes. Of course the valve needs support on the back face or the steam pressure would simply blow it off the valve face and connect all ports. This was overcome by using a balanced valve called an Andrews and Cameron valve.







Best Regards
Bob


----------



## steamer

Harold,

Do a search under "Rushforth" and you'll find it....don't want to hijack Brians thread.

Dave


----------



## Brian Rupnow

This is probably where I am going to go next on this build. The engines are finished, and the boiler is finished except for cosmetic fire door and ash clean out doors. My piping is on order from PM Research, and there isn't much else that I can do for the present. I have no idea at this time just how I am going to attach the gear to the shaft, but it may end up being a cross pinned solution. I can't make the hub any larger, due to clutch considerations, which means I don't have sufficient room for a key and set screw.


----------



## Brian Rupnow

Today I spent some time working on the large winch gear. When I bought the brass for this project, all my supplier had was 5" diameter. Not wanting to wait untill he ordered in another 12 foot stick of 4" diameter, I paid an exorbitant price for the 5" and had him part off one piece 1" long for the winch gear. I absolutely hate using my 4 jaw chuck, but need must when the devil drives and here you see a picture of what I was about today. I pared off the perimeter with my bandsaw, as I didn't want to turn it all into chips. Then I set the rather ungainly piece left up in my 4 jaw and turned the o.d. to 3.833: which is the o.d. of the 90 tooth 24dp gear I will cut, and then drilled, bored, and reamed the center hole all in the same set up.


----------



## Brian Rupnow

And here are the "parings" which I will save and use for little brass parts. Somehow my photo software has managed to turn this picture all cock-a-hoop, but you get the idea. This brass is too outrageously expensive to throw any usable bits away!!!


----------



## Brian Rupnow

There is my 'orrible, daggerous trepanning tool at work. Its a parting off tool ground to a long wicked point, and it seems to work perfect for trepanning. I take a series of 0.100" plunge cuts across the front face of what I am trepanning at about 250RPM, then a couple of .005 deep cuts all the way across at 1500 to smooth the ridges out. It works better than any other way I have tried to do this. The long 5/8" rod held in the tailstock chuck is not actually touching the part. Its about 0.040" clear of the part. I have had parts suddenly jump out of the chuck jaws while doing this type of operation and scare the Bejesus outa me, so I put that rod in as a "safety anti-jumper outer". I have yet to decide if I will leave that bit of remaining hub in and take it out in a later operation, or take it out now.---Brian


----------



## Brian Rupnow

Now I've put the 3 jaw back on and flipped the part around to machine the other side. I have intentionally left the 0.625" hub longer than necessary.


----------



## Brian Rupnow

Now here is a little mystery that I have never completely figured out, but I know from experience it is so. In my first set up, in the four jaw chuck, I turned the outer diameter of the part and drilled/bored/reamed the center hole all in the same set up.---Should be concentric, shouldn't it. However, when I mount the part on a snug fitting arbor and put it back in the 3 jaw, if I put a dial indicator on the outer diameter of the part, then rotate it, I get about .003 to .005 "run-out" condition. I assume that is an indication of the run-out in my 3 jaw chuck. I am going to "pin" that extra bit of hub on the trepanned side to the shaft, then when I move over to the 3 jaw in my rotary table I will grip he shaft, not the actual brass part which really doesn't have sufficient hub to hang onto. Remember that I need clearance for the gear cutter between the brass part and the actual chuck jaws.


----------



## Brian Rupnow

We have a 90 tooth gear!!! And the hub which was purposely left on the "wrong" side is now gone.


----------



## AussieJimG

"There is my 'orrible, daggerous trepanning tool at work."

You have set me wondering Brian. If you were considering removing the remaining bit of hub anyway, why did you not just use a boring bar? That is what I was planning for a flywheel that I am about to make and now you have me worried. What am I missing?

Jim


----------



## Brian Rupnow

I probably could have used a boring bar, but its a 3.1" diameter hole. thats more cranking than I want to deal with, but it probably works out the same.---Brian


----------



## AussieJimG

Thanks Brian, I thought I might have been about to make one of those mistakes that one has to post on HMEM with photos. You have set my mind at rest.

Jim


----------



## Brian Rupnow

Sticking with my theme of "Tell the truth even when it shows you're a dummy"----I went ahead and made the 12 tooth gear this afternoon. When I went to make it, I see that my charts call for a number 8 cutter. Damn---Thats weird!!! I haven't got a number 8 cutter. My cutters only go up to number 7.---Oh well, we'll use the number 7 cutter anyways---it will probably be close enough. Made the blank and machined the gear. Now, lets do a little math and calculate the center distance between the gears and we'll make a mounting block to see how they mesh.---Lets just check the solid model and make sure that the centers I calculated 5 weeks ago are the same. WHOA NELLY--They're not the same!!! Well, I'm not about to go back and change the bearing stands, so we'll use the center distance off the solid model. As you see in the picture---don't mesh worth poop!!! Okay----I'm not that dumb!!! Time to play detective!!! I know the pitch dia. of the large gear. If I take half that away from the center distance on my bearing stands, and multiply the answer by2 that will give me the pitch diameter of the pinion.---well, son of a gun!---Works out perfect for a 14 tooth gear!---And I have the proper cutter and 21 hole plate to make a 14 tooth gear. SOMEWHERE along the way, I got distracted and modelled a 12 tooth gear, but my overall design was based on a 14 tooth gear. No harm--No foul. Now I know why this is called a Donkey engine. I'm a donkey. Tomorrow I'll make a 14 tooth gear.----Brian


----------



## chuck foster

that 12 tooth gear is not an error..............it is the start of a new project................i myself have tonnes of parts to start new projects :

any pictures of the whole gear cutting process ?

chuck


----------



## Brian Rupnow

chuck foster  said:
			
		

> that 12 tooth gear is not an error..............it is the start of a new project................i myself have tonnes of parts to start new projects :
> 
> any pictures of the whole gear cutting process ?
> 
> chuck


Have a look here. the whole process, in technicolor.
http://www.homemodelenginemachinist.com/index.php?topic=17185.0


----------



## Brian Rupnow

And this, me darlin's is what I shall attempt to build today!!!


----------



## b.lindsey

Looks great Brian and the 12 tooth will probably come in handy somewhere else. Good on the detective work too !!!

Bill


----------



## Brian Rupnow

For those of you who asked, both here and on the other forum I post on---I start out by turning a gear blank to size. This has the outer diameter and face width of the finished gear, and the hub has the finished diameter and length. The bore is drilled and reamed while in the same set-up, and then I use Loctite to "glue" a dummy shaft into the bore. This dummy shaft has a countersink in one end to fit the nosepiece of my tailstock which you will see in my mill/rotary table set-up.


----------



## Brian Rupnow

The charts which I got with my rotary table and indexing plates, and with my gear cutters call for a 21 hole divider plate and a #7 gear cutter, which you see here mounted on its spindle. If you can see it, the circles of holes on the divider plate are numbered, and the circle of holes closest to the center are stamped 21 which means that is the circle I will be referencing.


----------



## cfellows

Thanks for that Loctite suggestion, Brian. I usually use a home made mandrel like one of those below for cutting my gears but I like your method, too.

The first abor has a #2 morse taper with a 3/8" draw bolt to hold in place. I use the second arbor with a 4", 4 jaw chuck that fits the spindle thread on my dividing head.

Chuck


----------



## Brian Rupnow

In this picture the blank mounted on the 1/4" arbor is held in the chuck attached to the rotary table. The tailstock is supporting the outboard end of the shaft to keep it from deflecting while being cut. The gear is mounted on the mill spindle arbor and set at the correct center height. That brass spacer you see between the gear blank and the chuck jaws is exactly that----a spacer. I have never cut a steel gear before, and I didn't want the pressure of the cutting action to slide the gear blank back on the arbor. The blank is held on its arbor with Loctite, which seems to be sufficient holding adhesion to keep the blank from moving. The 21 hole divider plate is mounted on the rotary table, and the sector arms are set to 9 holes. Note that means 9 visible holes plus the hole that the locator pin is in.


----------



## Brian Rupnow

And here the gear has been indexed 14 times and all the teeth are cut.


----------



## Brian Rupnow

And here is a short video of the gears meshing.


----------



## vcutajar

Brian

You have encouraged me to do my own gears next time. I have everything except the most important thing - the gear cutters. Obviously mine will be metric.

Vince


----------



## Brian Rupnow

And before I sneak out to get some lunch---Here's a teaser shot!!!


----------



## Brian Rupnow

I have to build two of these sliding clutch links today, and they look problematic. However, they are small. I think I will make one long piece with the correct profile, then part off the two pieces I need. they have to fit and run smoothly in two slots that I cut in my big brass winch gear.


----------



## ShopShoe

Teaser Indeed!

I just gotta say that the cost of the brass was worth it in appearance.

This whole project gets more interesting every time I look at it.

--ShopShoe


----------



## Brian Rupnow

My God---I hate making teeny weeny parts. Especially when they are made out of steel!!! Now if I had an hours creative filing time in on that big brass gear, I'd get those suckers fitted up. Then there are two even smaller pieces to connect them to the sliding collar. However, Jerry did it. And if a Floridian can do it, then darn, a Canuck should be able to.


----------



## chuck foster

nice looking gear brian and i for one have NO doubt you will make this whole bag of tricks work and look great.

if as you say "idle hands are the devils work shop" then i guess you must be the purist saint among us cause you hands NEVER seem to be idle. :bow:

chuck the sick canuck


----------



## Brian Rupnow

Itsy bitsy, teeny weeny, yellow polka dot---Donkey clutch parts!!! They work, and they seem to work very well. There is a world of "frigging" to get everything working freely and not bind, but once they are freed up, they work great. In the one shot showing the back side you can see the slider blocks that attach to the hardwood clutch shoes. I'm not going boldly where no man has gone before here. Captain Jerry had this mostly all worked out months ago.---But then again, he's got a captive Donkey in his back yard that he can run out and measure. I have only ever seen one of these critters in my life, and that was a number of years ago at Algonquin Park in Ontario. Foldks tell me ther is one about half a mile from my house over at the Simcoe County Museum, but I haven't been over to see it. I am rapidly closing in on the point where I have to build my winch drum and external clutch housing.


----------



## Brian Rupnow

In the middle of all this steam engine foolery, I just installed a new keyboard that seems to be incredibly small, although it is the "standard" model. When I first started to use computers about 15 years ago, I bought one of those big "ergonomic" keyboards, because I have huge hands and fingers. It has finally given up the ghost so I am using this standard keyboard now. Of course it doesn't seem as bad now, since I've had 15 years to practice where my fingers go!! ;D ;D


----------



## Brian Rupnow

Since these are finished and assembled, I may as well through the drawings into the stewpot!!!


----------



## Brian Rupnow

My remaining short piece of brass isn't long enough to build an entire winch drum out of, so I will build the two end sections out of brass and fill in the center with some form of pipe. Trouble is I don't know exactly what pipe yet, so that is an unknown dimension at this time. I can live with that---make the end bells now and figure the pipe out later. Brass would be nice, but I'm way over budget on this build.


----------



## ozzie46

Brian, How about a brass sink drain thingy? 


  Ron


----------



## Brian Rupnow

ozzie46  said:
			
		

> Brian, How about a brass sink drain thingy?
> 
> 
> Ron



Good idea Ron---I'll check at the plumbing supply house tomorrow.


----------



## Brian Rupnow

Another drawing to add to the ever growing pile----I made these today, but didn't take any picture of them before I installed them.


----------



## Brian Rupnow

However----This did let me assemble all the bits and pieces I've been working on. I've been too busy to hunt down a suitable piece of brass tube to connect the two ends of the winch, although I did stop at a couple of plumbing stores and check out the brass sink drain tubes---they were too small. So far, everything is working out well, and I will probably spend some time working on clutch parts and finishing the winch drum this week.----Brian


----------



## chuck foster

looking good as always brian, what diameter of brass tubing do you need ?
i have some pieces here at home and some at work let me know the o.d and the length and i will see what i can find.

chuck


----------



## Brian Rupnow

chuck foster  said:
			
		

> looking good as always brian, what diameter of brass tubing do you need ?
> i have some pieces here at home and some at work let me know the o.d and the length and i will see what i can find.
> 
> chuck


Well, in a perfect world, I'd like a peice 2.30" outer diameter by about 1/16" to 1/8" wall x 2 1/2" long. I can live with a bit smaller o.d., but can't go any larger.----Brian


----------



## kcmillin

Brian Rupnow  said:
			
		

> Well, in a perfect world, I'd like a peice 2.30" outer diameter by about 1/16" to 1/8" wall x 2 1/2" long. I can live with a bit smaller o.d., but can't go any larger.----Brian



Could you make it out of sheet brass, formed and soldered?

Kel


----------



## Brian Rupnow

Kel---I probably could, but I don't have a set of slip rolls, and brass thick enough to do the job would be really difficult to roll. I just haven't had time to persue this issue, and brass is far too expensive to make it from solid. I'll figure out something this week. I have a ton of other things to address yet, so I'm not in a time crunch for the pipe.


----------



## tel

Once the drum is laid with cable the bit of pipe will be invisible anyway - steel would be fine - even a bit of exhaust pipe tubing.


----------



## Captain Jerry

Brian

Use any kind of pipe and cover it oak lagging. Very authentic. Oak lagging had two benefits on the historical donkeys. To increase the drum diameter and line speed and to reduce cable wear.

Jerry


----------



## Brian Rupnow

This afternoon I built the clutch.---At least the wooden part that will become the expanding "clutch shoes". In the foreground is the piece of 3/4" thick oak flooring that it was made from. (A left over from when I had hardwood floors installed 5 years ago.) The process??---Well, first I drew a 3" diameter circle on the wood with an old drafting compass and "rough cut" it out on my bandsaw----And its darn rough, because my bandsaw has a 1" wide blade that is far more into cutting straight lines than curves. Then out to my big ancient drill press where I drilled and reamed a 5/8" hole in the center of the circle. I had bought a piece of 3/4" brass rod to make the winch shaft bushings from yesterday, and about 3/4" of length was turned to 5/8". I mixed up a small batch of 2 part epoxy and gobbed it on the turned down section, slid the wood over the shaft, then went and eat my supper. Came back downstairs after supper and turned the o.d. to an exact 2.8" diameter. Faced the end farthest from the chuck. Then came in from the back side and took repetitive cuts untill it measured exactly 1/4" thick. There is a 3/8" hole about 1/2" deep in the end of the brass rod. Tomorrow I will bore the brass rod away in small incrememts utill I am left with the hardwood disc with a 5/8" hole in the center. The solid model shows what this wood will eventually look like. (The solid model of course shows only one clutch shoe---there will be two of them both made from this single wooden disc)----I hope!!!


----------



## Brian Rupnow

Well of course I'm going to give you a drawing of it!! You thought I forgot, didn't you-----------EDIT EDIT--Drawing has been revised. Center radius was originally .313"


----------



## miner49r

Brian,
  I have been following your build since the beginning and I am at a loss for words. I hope that some day my skills would come somewhere close to the exacting work that you are doing.
  Any thoughts as to how much horse power (or watts) your engine puts out?
Alan


----------



## Captain Jerry

Brian

I have been looking at your drawings and if I haven't made an error, something is not
fitting. Looking at the slider in the clutch mechanism, the bottom of the shoe that fits into the
slot in the wooden clutch shoe is .375" off of the face of the gear plate.

   Total height   .400"
   Slot Width   - .125"
    Top Flange  - .080"
          ---------
   Total      .375"

And the wooden shoe, after subtracting the depth of the slot adds .100" for a total of .475"

The internal depth of the drum is only .375" which means that there must be a gap between the
face of the gear and the lip of the drum of at least .100" and that is if the face of the wooden
shoe bears against the face of the drum, which it definitely should not do. The only contact
between the drum and the shoe should be the outer edge of the shoe.

I dont see anything that will maintain the relative position of the gear and the drum on the shaft.
What is there to keep the face of the clutch shoes clear of the drum face?

In my design, the inner face of the clutch drum bears on the end of the gear hub, with a bronze
thrust bushing between. The depth of the hub and the bushing keeps the gear and clutch drum 
separated by about .015" and also maintains a clearance of about .015" between the shoe face and
the drum.

In this post, where I mention the shoe face, I am talking about the flat face of the disc, not the
edge of the shoe.

It is entirely possible that I have misinterpreted your drawings or added the numbers wrong.

Jerry


----------



## Brian Rupnow

Jerry---maybe this will help. In the picture the slider you see on the smooth face of the gear sticks out a total distance of 0.275---that is .125 plus .150  In the drawing of the clutch shoe, the remaining amount of material below the 0.150 recess is 0.100 If you add .275 of metal plus .100 of wood, that is a total of 0.375, which is the depth of the counterbore in the end of the winch drum. Shouldn't in theory be any gap. However---Where the drawing shows a 0.013 clearance between the end of the gear hub and the inside face of the winch drum, I will probably make up an 0.025" brass spacer to fill that gap and give me 0.012 clearance where there is now no clearance at all between the back side of the gear and the end of the winch drum. Another thing I just noticed is that the wooden disc can't be "size on size" with the 2.8" bore in the winch drum AND the 0.625" hub on the back of the gear. I will open that hole in the wood to 11/16" thus giving a possible movement of 0.031" to each clutch shoe as it engages and disengages. ----Brian


----------



## Jasonb

But without a gap you will get a lot of friction between the side of the winch drum and the sides of the wooden clutch parts, I think that is wat Jerry is saying and I agree.

J


----------



## Brian Rupnow

Jason---That is a theoretical, mathematically possible "zero gap". In reality there will be a gap, but it will be very small.---I control that.


----------



## Brian Rupnow

Yes Virginia, you can bore wood with a carbide tool-----If thats the only kind of boring tool you have!!!


----------



## Brian Rupnow

And here's what the finished wooden bits look like laying in the cavity in the end of the winch housing.


----------



## Brian Rupnow

This is the wooden bits attached to the sliders that slide in slots in the big gear---


----------



## Brian Rupnow

And here is the whole clutch "buttoned up".---But, as Ringo says, "It don't come easy!!!!" Only I and probably Captain Jerry know the ammount of pure "Friggery" involved in getting all those little pieces together. The clutch seems to work, but I haven't had the time to properly test anything today. My real work is interfering with my "play work".


----------



## AussieJimG

The wood boring came out well but Yuk - the mess. And all around the air intake to the motor too. But I have done similar things and the lathe survives.

That clutch is looking good and nobody but you and Jerry will ever know the secrets it contains.

Jim


----------



## archer3d

AussieJimG  said:
			
		

> That clutch is looking good and nobody but you and Jerry will ever know the secrets it contains.
> 
> Jim



I agree completely that it is looking great, but there are a lot of people watching here that will thankfully know the secrets  

Tom


----------



## Jared

Brian, now that you've got the design nailed down I come along with this: http://www.ebay.com/itm/1912-Clyde-...04863?pt=BI_Books_Manuals&hash=item4601b5d67f


----------



## Brian Rupnow

Depending on how the day goes, we may have an operational winch by the end of the day.


----------



## Brian Rupnow

We be gettin' closer!!! I picked up a piece of bronze tube this week for the best of all prices (free), and it has become the center for the winch drum. This afternoon I will work on the shaft.---The whole winch drum assembly is just setting on top of the bearing caps right now, waiting for the Loctite to set up.


----------



## cfellows

Lotta brass on that engine, Brian... wonder if it would've been cheaper to make it out of 14K gold??? :-\

Chuck


----------



## Brian Rupnow

Look close----Look real close----Can you see the string hanging down from the winch drum? Thats not a dead rat hanging on there----Its a five pound chunk of steel. I've been clutch testing. See that round piece of brass with the 3/8" rod sticking out of it, just to the left of the Donkey set up?---Thats my clutch activator. It works like this---I had my electric drill on the bit of winch shaft that sticks outside the bearing cap on the opposite side from the gear. I would turn on the drill, slowly, and it would turn the shaft and gear slowly, but the winch drum just set thare and didn't revolve. Then with the drill running I would poke that drill activator thingy down the hole drilled in the center of the winch shaft and push on the cross pin which caused the clutch shoes to expand and grip the inside of the drum. Then things would get exciting real fast, because the drum would start revolving and that chunk of steel would start climbing up towards the winch drum as if it was a live rat!!! Scared the Hell out of myself a couple of times. Sometimes the clutch would disengage when I let the pressure off the clutch activator, and sometimes it wouldn't. I plan on putting a compresssion spring in behind that cross pin to ensure that the clutch disengages when I want it to. i didn't have enough hands left over to make a video like Jerry did, but the clutch works fine.


----------



## Brian Rupnow

Here is a larger picture of the "clutch activator thingy" inserted in the end of the winch shaft. It will be replaced by a lever mechanism with a scale sized handle as the build progresses.


----------



## Brian Rupnow

cfellows  said:
			
		

> Lotta brass on that engine, Brian... wonder if it would've been cheaper to make it out of 14K gold??? :-\
> 
> Chuck



Chuck----Its unbelieveable!!! Counting the cost of the brass, the scale model piping and elbows that I haven't shown anything about yet, and other miscellaneous bits, I have close to $500 in materials in this engine. I'm happy with the progress I've made, and things I have learned, but its turning out to be a very expensive engine.----Brian


----------



## Captain Jerry

Brian

If you are not feeling pumped, then your life experience has been way more exciting than mine. When I first lifted a chunk of metal with my clutch operated winch, I could hardly contain myself. It's about 100 yards from my shop to the nearest restroom facility in the horse barn and when I got back to the shop, I spent a lot of time making that weight go up and down. A truly enjoyable experience and I congratulate you on reaching this stage of construction.

I can truthfully say that I have never experienced a tendency of the clutch to hand and not release. In my first test, I used and external power source to drive the winch shaft directly as you have done. In later tests and demonstrations, I have powered the winch via the small gear on the crankshaft, again with no tendency to hang. Your clutch is almost identical to mine, with a few very small differences in detail mostly related to the slight difference in scale. If you have not already resolved the problem, here are a few suggestions.

Make sure that all sliding surfaces of the mechanism including the face and slots in the big gear are polished and lightly lubricated.

Make sure that the slots of the sliders are also polished and lightly lubricated and that all corners of the slider slots are eased or slightly radiused.

If you have used a spacer between the gear hub and the winch drum, be sure that the spacer and the surfaces that it may contact on the gear hub and the winch drum are well polished and lightly lubricated. There should be no pressure on this contact face and I would advise a gap of at least .0005".

These are just some thoughts that might help to smooth out the operation but as I am sure you know, the best tool to use here is the fiddle. A couple of courses of intense and enlightened fiddling will have that thing working just the way you want.

It's looking good. keep at it!

Jerry


----------



## Brian Rupnow

This morning I installed the pinion gear on the shaft between the two cylinders. This is far more complex an operation than you would give credit to, as it involves removing both flywheels and timing cams. After a morning spent realigning everything and chasing down "tight spots" I have everything back together and running reasonably well, but it appears i may have the engines running in the wrong direction. Oh well, thats easy enough to change. i'm happy with the results, and can now probably move on to the clutch lever part of the build.


----------



## lazylathe

Awesome stuff Brian!!!!

Will you be able to reverse the drum rotation so as to unwind whatever you have previously winched up?

Can't wait for this one to be completed!

Andrew


----------



## Brian Rupnow

Andrew---No reverse on this one. This is a logging model, not a lifting donkey. The clutch/winch was put into freewheeling mode, and the cable pulled by hand back to the next tree. That is why this one had no ratchet on it either---It wasn't used for lowering loads.


----------



## SBWHART

Cracking Job Brian :bow: :bow: :bow:

Looking forward to the next bit

Stew


----------



## firebird

Very nice Brian :bow: :bow:

Very nice indeed :bow: :bow:

Cheers

Rich


----------



## lazylathe

Thanks Brian!

Taking all that into account are you going to making some scale logs?
I have been pruning the oak tree and can send you some!

All your builds are great reads!
My favorite thing about all of them are that you build an engine and then you build something else so that the engine has a function!!

Andrew


----------



## Catminer

Well that is nifty! Keep up the good work Brian

Peter


----------



## Brian Rupnow

My good wife is upstairs doing the (shudder) income tax for 2011, so I snuck as far away as possible and came down to my design office to see what I could do to stay far away and out of the way!!! I guess the next trick is to have something to actuate the clutch mechanism with, so drawing directly from Capatain Jerrys expertise, I have drawn up the "activation block" that attaches to the gear side bearing stand. I will build it next.


----------



## Brian Rupnow

And another one bites the dust!!! I just finished the clutch activator block and bolted it onto the bearing stand to make sure all the bolts line up-----They did!!! As you can see from the grease around the clutch sliders, I have been "fiddling" with the clutch mechanism and now have it working much smoother. I did put a small compression spring inside the winch shaft which bears against the cross pin to ensure that the clutch disengages each time it has been engaged and it works much better now.


----------



## Brian Rupnow

Well, I have just about used up the whole day clutching. Wife finished the horrible income tax, and if all goes well, I think we only owe $11 to the government. This is the first year with both of us drawing pensions, and if we hadn't been able to do "Pension splitting, which is a relatively new thing in Canada, we would have had to pay $2000!!! Quite a difference!!---And if the Donkey Gods smile on me, I may have a video of the clutch operating tomorrow.


----------



## te_gui

Brian, 
Trying to figure out how your clutch lever will work. I know on the full size Willamette I restored, the clutch lever turned a multi-start screw that moved the frictions in and out against the drum, but your drawing shows just a thru hole. Waiting to see what you have up your sleeve.

Brian


----------



## Brian Rupnow

It takes a bit to explain how that clutch activator works, but here goes--


----------



## Brian Rupnow

And of course there has ot be a pin to engage that angled groove---


----------



## Brian Rupnow

Here is a drawing of the spacer that acts as a "stand-off" between the bearing support and the clutch activator block.


----------



## b.lindsey

It just keeps getting better and better Brian. What a nice addition the little donkey will make to your already fine collection!! Looking forward to the clutch video as well.

Bill


----------



## Brian Rupnow

Now, if you have a really good imagination, you can see what happens when all those parts are assembled. When the handle is swung thru an arc, the 3/32" pin loctited into the center of the #10-24 shcs is always engaged with that slot, forcing the rotating pin to move foreward. Thats what puts pressure on the cross pin and eventually thru a set of sliding linkages causes it to expand the clutch shoes.


----------



## Captain Jerry

Nice design. Very clever.

Jerry


----------



## Brian Rupnow

Captain Jerry  said:
			
		

> Nice design. Very clever.
> 
> Jerry



Okay Jerry---I fully admit, its your design, and I have given you credit for it a number of places throughout this article. I am posting the detail drawings so others can build a similar clutch device if they wish to. I am seriously burned out on this project right now, so I'm taking a break from it, doing yardwork and getting things ready for spring around the homestead. I will get back to it. I have to decide on whether or not I am putting a brake on it, and I have all these nifty cast Tees and elbows from P M Research to make a proper steam plumbing set up for the model------When I get over some of the current burn out.


----------



## cfellows

Wow, Brian, seriously, yard work as a break? Yeah, I know, it has to be done but I sure don't like it myself!

Chuck


----------



## miner49r

Take a break and regroup Brian. The meticulous work you are doing on this build has to very taxing on the mind. 

Sometimes I look forward to mowing the lawn. The droning of the engine seems to block out the worlds troubles and distractions. Occasionally, I will come up with the answer to meaning of life... Turn the mower off and it's gone. ;D
Alan


----------



## Brian Rupnow

Looking back to the beginning of this thread,it seems that I started it on or about 28 January. Thats not so long ago, only about 7 weeks. However, I've machined something and posted about it practically every day. I'm badly burned out right now, and today is so unusually warm for March that I had my roadster pickup out for a spin. ;D ;D I have to wait a bit now until this build starts being fun again before I resume.----Brian


----------



## AussieJimG

After 7 weeks of continuous work and a long, cold winter such as you have up there, it is no wonder that the call of the warm weather is so strong.

Like your previous projects, this build has been a really enjoyable journey; something inspiring nearly every day. The time and trouble you took to 
document your work is much appreciated.

I feel sure that the burnout is temporary and that you will once again derive pleasure from building something and that it will be unusual and challenging.

Whether or not you do anything else to the Donkey Engine, it stands as a monument to your ingenuity and skill.

I wait with patient anticipation for the next Brian Rupnow thread.

Thanks
Jim


----------



## Harold Lee

Brian Rupnow  said:
			
		

> SNIP>>>>
> 
> I'm badly burned out right now, and today is so unusually warm for March that I had my roadster pickup out for a spin. ;D ;D I have to wait a bit now until this build starts being fun again before I resume.----Brian





			
				Brian Rupnow  said:
			
		

> Maybe its the time of year, or, maybe its the time of man.---I'm sick to death of working on my Donkey engine. I've been threshing on that sucker for 3 months or so, and today Wife and I took the grandkids to the park and said to heck with it. Maybe I'll feel more motivated tomorrow, or maybe it won't happen until fall.----Brian



Even though I would like to see your donkey running and completed, it will be in your shop waiting for you whenever you get ready for it.... The Roadster will even still be there waiting to take you out for another ride.... BUT those grandkids will be grown and gone before you can blink your eyes... It seems they grow up even faster than their parents and any time spent with them will never be regretted or wasted... Enjoy your hiatus and we'll look forward to seeing your project progress after the more important tasks are attended to....


----------



## Captain Jerry

Brian

I fully understand the frustration and burnout on this project. My own donkey project got put under the bench for many months at about the stage that yours has reached. It has been resurrected now with your encouragement and although my posting has been erratic, I think I'm back on track.

I don't know what the problem is with these things, but they do wear you down. Your working speed is much faster than mine and I though that momentum would carry you through. But you don't have to worry. You will have a different viewpoint after a short break.

Jerry


----------



## Brian Rupnow

I had a bit of time this morning to "play", and I found this excellent post showing how to make a simple jig for machining the cast pipe elbows as purchased from P M Research
http://www.homemodelenginemachinist.com/index.php?topic=13686.0
I followed the instructions and built the jig, and it seems to be just great.
 I followed the rough sketch, although the only REAL important dimensions are the 0.320" offset from face of block to center of hole and the 5/16" and 3/8" drill diameters. I found that I had to use my Dremel tool to remove a very small bit of material from both "halves" of the jig on the inside corner, as my elbow castings don't have really "clean" inside corners, but other than that it seems to work fine the way I did it. Thank you MetalButcher for the neat "how to" post and the drawing.---Brian----(And Oh Yeah,---I found that the 3/8" diameter counterbore needs to be .062" deep from the face of the jig.)


----------



## Brian Rupnow

Here is my first succesfully machined and tapped elbow. I used a 7/32" dia drill and only drilled .33" deep from where the tip first contacted the flat machined face of the elbow, then tapped with a 1/4"-28 tap. I found that when using MetalButchers original drill depth of 0.4" that the tip of the drill broke through the far side of the elbow. Even at a drill depth of .33" there is still plenty of open passage for air flow, and using a standard tap (not a bottoming tap) seems to get a sufficient depth of threads into the elbow.


----------



## Brian Rupnow

This is a rather questionable shot of a threaded pipe engaged with the machined elbow. I used the brass pipe purchased from P M Research, 1/4" o.d. x 3/16" i.d. Even with the 1/4"-28 threads cut on the outside of this pipe, it still seems to have sufficient wall thickness in the threaded area. I was able to get full engagement of 6 threads when screwing it into the threaded elbow "by hand'----although I do have pretty powefull hands. I didn't want to spend the money nor take the time to buy 1/4-40 taps and dies, and since i will be using Loctite as a thread sealant, I am not concerned about air leaks.----Brian


----------



## Brian Rupnow

Well!!! Isn't that a fine kettle of, umm-----ELBOWS!!!! Other than the one I ruined by drilling it too deeply, the elbows all survived milling and threading. I did end up going over them all with a 1/4"-28 botoming tap and found that I could get 3 more full turns on the tap handle. I'm not sure they will all see use on the Donkey, but they will get used sooner or later. Plus, I have all the bits still attached to the casting tree. Only one thing to say about what you see here. The parts only cost a total of $25, but when they got to my house the shipping was another $25 on top of that-----So=====There are $50 worth of miniature fittings in that picture.----OUCH!!!


----------



## JorgensenSteam

Its not that big a deal to put a core in something like that.
They should core those things.


----------



## Jasonb

Pat the likelyhood of a 7/32" dia core failing or shifting are quite high, trying to pour an item with a wall thinkness of approx 1/32" and getting the whole mould full is also not easy as the metal will cool very quickly and then there is also the added cost of making and placing the core.

Another thing to remember is that Brian is using the relatively large 1/4" fittings don't fancy trying to core a tree of parts when the core is not much more than 1/16" which it would need to be on the fittings for 1/8" pipe.

Talking to people having things cast recently or pattern making and the general comments comming out of the foundrys are that if its under 1" dia core then it not really worth bothering unless its something particular like a steam passage. The cost of the extra metal used will outway the cost of teh core and the risk of problems.

J


----------



## Brian Rupnow

I'm back to playing with my Donkey. Last week when I had to disassemble everything to install the pinion on the looooonnng crankshaft, I just couldn't get all the binds out of the system to let it run correctly when I reassembled it, and when I did get them out enough for the engines to run, the damned things ran backwards. Of course, I was fiddling with the clutch, trying to get it to work correctly, and things just weren't working out. A few days break was needed. Today i snuck up on things by machining and tapping all the pipe elbows first. Then I retimed things and got both engines turning the correct direction. It still has some serious binds in it, but I find that if I loosen all the fasteners off untill the engine runs freely, let it run for half an hour, then tighten everything a bit, then let it run some more, I can tell when the engines start to rev faster it is time to tighten the fasteners another 1/2 a turn. This of course slows the engine down again untill it wears the tight spot in, then it speeds up again. Eventually, with enough repititions, all the tight spots should be gone and the engine should run much slower and smoother.


----------



## Brian Rupnow

This is the clutch video I was trying to make last week when I got so disgusted and had to quit for a while. The engines are running much smoother now, (Turning the right direction) and the clutch is working pretty well as its supposed to. I have found one "caveat" that I may do something about, or I may not. I chose to make my winch drum 2.3" diameter, just because to me that looked to be about the right size to fit the scale of the whole project. The caveat though, is that with a larger diameter drum, the radius arm from the center of the winch drum to the center of the cable is longer, requiring more power from the engine to turn the winch, thus requiring that the engine run at a faster RPM than I really like. It "looks" right, but it would probably have been better if I had went with a 1.25" diameter winch drum. The part being lifted would raise more slowly, and the engine wouldn't have to work so hard. Of course, the question is, do I really care? I will probably fill the drum with one layer of cable for "looks" and the clutch may never be used again. This is a model engine, not a working engine, and unless I rent it out to the local elves or field mice, the clutch operation doesn't mean all that much.


----------



## Jasonb

Brian this comes back down to throttle control. If you up the psi on your compressor you will get more power but as you say the engine runs faster. Now leave the compressor at those higher settings but fit that control valve and you will be able to regulate the speed by controlling the volume of air but still have power and the rpm you want.

J


----------



## Captain Jerry

Brian

Looks like the clutch is working nicely. I agree that a smaller diameter drum would have given you a little more power and control but it will improve as the engine wears in and settles down. As Jason says, control valve at the engine would make a world of difference.

Jerry


----------



## miner49r

Looking and running good Brian. There is definitely a method to your madness.
Just tell the garden gnomes that if they don't like it they can go back to using snails and a block & tackle.
Alan


----------



## Brian Rupnow

I guess the time has come to mount my "steam" control valve and figure out my "steam" lines.


----------



## cfellows

Nice running engine, Brian. The clutch and winch do work well. 

Chuck


----------



## Brian Rupnow

Thanks Chuck!!! I had posted this bracket once before today, but then it immediately underwent such major changes that I just deleted it untill I had it redesigned.---Brian


----------



## Jasonb

Brian are you going to run the exhaust pipes back upto the cowel like the original? if so it may get a bit messy around the top of the boiler. I would be inclinded to bring the feed down the back of the engine and then tee off to each cylinder with a linkage to take the valve control to where the operator would be.

J


----------



## Brian Rupnow

There! That takes care of my control valve bracket. Now I can mount it as per the solid model. Jason---There are no exhaust pipes per se'---Just steam escape vents on the underside of the cylinders.


----------



## Brian Rupnow

I'm getting out of sequence here, but by adding one more counterbore to the elbow drilling jig I built the other day, it worked perfectly well to machine, drill, and tap the 1/4" pipe Tee.


----------



## Brian Rupnow

Damn, Sam---Thats a lot of drilling and tapping and thread chasing!!! I didn't need all of those 90 degree elbows, but I had a jig and I was on a roll. The 45's were harder as i had to open the jig and turn the part end for end to machine/drill/ and tap both ends.


----------



## miner49r

Those fittings look great. I dislike tapping myself. And stop calling me Sam.


----------



## cfellows

They look great, Brian! Of course, you are going to file off all the flashing then polish them up to a high luster, right!  

Chuck


----------



## Brian Rupnow

Here we have a tale of bad luck, over confidence, or just plain old "dumb-assedness". First the good news----The boiler is painted with "Chassis Black" by VHT paints, which gives pretty well exactly the color and "hue" that I wanted. Not glaringly glossy, and yet not "flat black" either. The far side of the base is drilled and tapped for an air hose fitting in a very inconspicuous spot, and the air passage surfaces inside the boiler, where it connects via a flexible line to the "steam pipe" which exits thru the side of the stack and into my home made control valve. That part went very well. It was only while assembling all the piping to the cylinders that I discovered a mistake (can't call it anything else) that I had made. However I managed to do it, the cast 45 degree elbows are tapped in such a manner that they have a contained angle of 130 degrees, instead of the 135 degrees that they should have. This means that there is no way that I can assemble the piping as I had planned, as per the 3D model. I tried to heat one of the fittings, and "persuade" it to bend another 5 degrees, but the picture shows the result I had doing that. SO----I'm down four 45 x 1/4" cast elbows, and the minimum order from PM Research is $25. I toyed with the idea of machining 4 elbows from barstock, but I could never match the nicely cast 90 degree elbows that are okay. I'm kind of stuck for now, but I'll figure something out!!!----Brian


----------



## tel

OUCH! Not good! You might have better luck bending the sections of pipe between the elbows.


----------



## miner49r

Brian,  
  You are methodical and meticulous with all that you do. From your career as a designer, hot rod building, to hobby machining. I would be very surprised to find you are at fault here. I went back and had a second look at your fitting. Besides 1 or 2 being a tad off center they look great. There must be some unforeseen circumstance. Either the castings are not truly at 45 degrees or they cocked a bit in your jig. 

Now for the fix.
  Place the fitting back in the jig. Now that you know the amount of error you can shim the jig in the mill vice to what would essentially be "correct". Chuck your tap and chase the threads at the corrected angle. Yes, the threads will now be sloppy. Do your trial assembly to get all your plumbing the way you envision it to be. Then upon final assembly apply something like epoxy to the sloppy threads to create the seal. 
  No shame in it. I've used epoxy on pipe threads on all my compressor installations and they never leak down.
Alan


----------



## Jasonb

As its only on air you may get away with tightening up your die and cutting the pipe thread deeper which will give enough wobble to get the angle right, assemble with JB Weld or epoxy and it should be OK.

Was the jig machined wrong if they are all the same error??

You will likely also have to turn up some nutted unions as you won,t be able to screw the last fitting/pipe into place, it also makes disassembly easier, some thing like these

J


----------



## tel

> You will likely also have to turn up some nutted unions....



.... or flanged joints, thus, which might be more in keeping.


----------



## Jasonb

Tel its an American engine they all use screw fittings ;D Allows more leeway to get things lined up 

J


----------



## tel

;D Fair enough, and a big 'ammer to make sure they do?


----------



## Brian Rupnow

All is well! I called PM Research and explained my dilemma, and they are going to ship me out a "stick" of 45 degree cast elbows.


----------



## b.lindsey

That's good news Brian. I ahve always found the PM folks to be good in the customer service area. I wish they didn't have th $25.00 minimum at times, but I can understand their side of that. The winch test looks great btw !!

Bill


----------



## Brian Rupnow

tel  said:
			
		

> .... or flanged joints, thus, which might be more in keeping.



Tel---That is an elegant solution. I may do that.--Brian


----------



## Jasonb

Ah but then you will have to change to flanged bends to go with them  ;D


----------



## Brian Rupnow

Nothing new build wise, as I have been seriously side-lined by some "real" work. However, I do have a question for those more knowledgeable than I am about these donkey steam winches. Obviously these winch drums had lots of cable on them, and it wouldn't always be in use. So---What did they do with the hook or whatever was on the end of the cable when it wasn't being used, but the engine was being run. They couldn't just let it flop and clatter around. Did they have a way to anchor the hook to the winch itself (which wants to turn even when the clutch is not engaged) or did they anchor the hook to something solid that wasn't part of the winch.---Which would seem pretty dangerous to me in case somebody engaged the clutch and pulled the machine apart. I'm curious, and since I don't plan on doing any real serious winching with my model, I may just lay up one complete wrap of rope and varnish it in place---but I'm not sure what to do with the hook at the end.----Brian


----------



## archer3d

Brian 
Some of the old steam driven boat winches I've seen just had a hole the size of the cable towards one end of the barrel, the cable was inserted into then wound round the barrel with the only hook being on the end. The only problem with this is that if the cable was run out all the way it would just come off the spool.

tom


----------



## Captain Jerry

The biggest problem with these or any drum winch is called over wrap, which happens when the line goes slack and forms some loose wraps that overlay the working end. When the clutch is engaged and the line goes tight, the overwraps capture the working line and bind it tight. It often happens when a line is paid out from a free wheeling drum. The operator has to control that with the brake when paying out.  The first time you went fishing, you learned to keep your thumb on the reel.

Another point worth mentioning is that these engines have no governor. The operator has to throttle back or stop the engine as he de-clutches or otherwise releases the load. That is why the throttle or steam control valve is handy to the operator position. On any application that includes a boom, the weight of the hook should keep the line tight. If the end of the boom is very high, it is possible that the weight of the line on the inhaul side of the boom can exceed the weight of the hook so if you pull the hook up to the boom tip, it can't fall back under its own weight, so an extra weight, called an "overhaul ball" is added to the end of the line.

But, to answer your question about a simple winch with no boom, I don't know, but I think I would weld a hook somewhere on the front of the frame. You still have the problem of the line going slack when the engine is stopped with the clutch is disengaged. Ratchet pawls would help or some way to lock the brake.

Jerry


----------



## Jasonb

Brian Rupnow  said:
			
		

> Did they have a way to anchor the hook to the winch itself (which wants to turn even when the clutch is not engaged)



I think you will find on the full size that the drum won't turn when the engine is ticking over as there is far more weight in the drum, running resistance, resistance from the cable etc. than the lightly loaded model drum and string. Put some steel cable onto yours and it won't freewheel, I know the model traction engines with their winding drum behind the nearside wheel take quite a bit of winding and thats still quite light cable - 1/16 on the one in my avitar and 1/8" on teh Fowler I'm building.

J


----------



## Brian Rupnow

I had a bit of spare time today, and I've been thinking about firebox doors---Well, not the door itself, which will be brass, but rather the door frame which will probably be made from aluminum and painted "chassis black" to match the rest of the firebox/boiler. It is beyond my capabilities to make an oval one like the one on Jerrys Donkey. It may even be beyond my capabilities to make a rectangular one. I can plainly see some lathe face-plate work here to turn the 2" radius on the side that fits against my existing 4" diameter firebox. I see plenty of ball nosed cutter work forming all of the radii. One counterbored 1/4" bolt will hold it in place (Remember, its not functional). It should certainly be a challenge, at any rate!!!


----------



## Brian Rupnow

Something like this----


----------



## tel

Looks more like a case for fabrication to me - a curved plate with the central block let through it and silver soldered together.


----------



## Brian Rupnow

Tel--I agree with you. However, I don't have any curved plate. I don't have any way to curve plate if I had flat plate. I have all kinds of aluminum "chunks" laying around but it can't be soldered with anything I have. Besides---I've had that 10" faceplate ever since I bought the lathe and I don't think I've ever used it. If I screw it up, all I will have lost is a bit of my time.


----------



## tel

;D Cut a bit out of the side of a hunk of pipe.


----------



## Jasonb

Bend a bit of copper around your existing boiler barrel, you could virtually do it by hand. Then just solder a block of brass to it that has been cut to the curve, could even just be filed to a rough curve and stuck on to the copper with JB Weld as its only a show item.

Using these methods its only one step further to file the two parts to an oval shape.

I find the challenge of finding new ways and methods to make things one of the main things with model engineering, why limit yourself to what you are comfortable with, the satisfaction at the end of the day with a part that looks like it should is worth the effort trying new things out.

J


----------



## tel

> I find the challenge of finding new ways and methods to make things one of the main things with model engineering, why limit yourself to what you are comfortable with, the satisfaction at the end of the day with a part that looks like it should is worth the effort trying new things out.



Yer got my vote there - every day a new skill!


----------



## Brian Rupnow

Well, for me, doing just about anything on a faceplate is learning a new skill!!! I'm not sure that what I am going to attemp will work, but nothing ventured, nothing gained.


----------



## Brian Rupnow

Well There!!! That wasn't too bad at all. Other than a lot of handle turning, I didn't see any real problem with turning an interupted cut on a faceplate. I'm sure it would have went even better if I had taken the time to sharpen that carbide boring tool, but right now, with all the house renovation going on, I can't get to my grinder. I have a lot more work to do before I dismount the part from the faceplate, but so far, so good.----And yes, I did drill and tap two #10-24 holes in the faceplate to hold the part on there.


----------



## smfr

Oh, good use of the faceplate! I was thinking that people always used a flycutter on parts like this.

Simon


----------



## Jasonb

The advantage of doing this part on the faceplate rather than flycutting is that Brian can now come in from the outside with a round nosed tool and create the curved end flange, then flip the part over to do the same on the other end.

Same could be done using a rotary table. Could be done with a flycutter than switch to a boring & facing head but if making from solid then the faceplate is best bet.

For anyone who does not want to drill their faceplate the work could have been screwed to a bit of scrape flat bar or plate which in turn can be clamped to the faceplate, this does allow for fine tuning of the part if you want to clock the centre position true.

J


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## Brian Rupnow

Stage 2---Hey!!!---I'm really liking this!!!


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## Brian Rupnow

Well there!! That was almost too easy. I had ground a 1/16" radius on my lathe cutting tool, so I have the radius as called for in the drawing. I think the project will move to a new level of difficulty when I take it off the faceplate and move it over to the mill. ;D ;D


----------



## Brian Rupnow

Set the part up in the milling vice at the appropriate angle and "mill to the line" with a 1/8" ball nosed cutter.


----------



## Brian Rupnow

And a bit of milling with a flat faced endmill---


----------



## Brian Rupnow

So there we go!! All I lack is a little creative file work and some paint. I didn't find that working with a faceplate on the lathe was a big deal. I'm pleased!!!


----------



## miner49r

Looking good Brian. I have to remember that the face plate isn't just for wood.


----------



## Brian Rupnow

I had so much success building a firbox door frame that I may try my hand tomorrow on the actual brass firebox door------


----------



## Brian Rupnow

I now have a brass door for my firebox. Every time I machine something, I learn something. Todays lesson was "Never machine a recessed area with any expectations of getting the machining marks out afterwards." The door turned out great. The finish ----Well, its good everywhere I could hit it with a polishing wheel.


----------



## smfr

That looks awesome! :bow:


----------



## Catminer

That turned out very well Brian

Peter


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## miner49r

Bead blasting would should mask the tool marks and leave it looking like it was cast.


----------



## Brian Rupnow

I moved the holes from their location on the model, because I had a damned end mill dig in where those holes are, on almost the last step. Rather than scrap the part, I moved the holes to hide the gore mark. I also found out after the last post that fine sandpaper wrapped over the end of a squared off popsicle stick takes out most of the machining marks.---Brian


----------



## lazylathe

Door looks great to me Brian!

What i find works really well is those small cotton mops you can get for the Dremel.
A bit of Brasso or fine polishing paste and a bit of time and it will be shining!!!

Let me know if you want some of the mops!
I can send you up some to try!
I also have varying grades of the scouring pads that will fit dremel tools!
PM me if you are interested in trying some out!

Andrew


----------



## Jasonb

Looking good Brian, shame the hinge lugs were not machined into the flange but as its a dummy door you should be able to mill a couple of slots and bond something in and then file to shape. Thats one of the disadvantages of alloy, you can't silver solder a bit on.

J


----------



## Captain Jerry

Brian

I think the off center draft holes add just the right touch. Good thinking. Not actually "out of the box" but "edgey."

Jerry


----------



## Brian Rupnow

I was so impressed with the way my firebox door turned out that I simply HAD TO add a pair of hinge bars for the door to swing on. I milled a couple of 1/8" slots in the frame and epoxied in a pair of hinge bars, then resprayed it with the "chassis black" enamel.


----------



## SBWHART

Thats a fine bit of deatiling on the door Brian

Stew


----------



## Captain Jerry

Brian

I think you are going to wish you had drilled the holes for the hinge pin and tested the swing before painting.

Jerry


----------



## Brian Rupnow

sbwhart  said:
			
		

> Thats a fine bit of deatiling on the door Brian
> 
> Stew


Stew---Thanks. I have just about ran out of things to do on the Donkey until my new 45 degree elbows get here from P.M. Research. I am still undecided about adding a brake. I do want to blow everything apart for painting and detailing, but not until everything is completed.


----------



## Brian Rupnow

Captain Jerry  said:
			
		

> Brian
> 
> I think you are going to wish you had drilled the holes for the hinge pin and tested the swing before painting.
> 
> Jerry


Well actually Jerry, it isn't going to swing. The door frame is solid, with nothing but a counterbored hole in the center of it to bolt it to my firebox. The doorframe will attach with one 1/4" shcs, and the brass door will be epoxied in place.


----------



## Brian Rupnow

HURRAY!!!!! My elbows just showed up from PM Research. If I can find some time now, and not screw these ones up, we will have a fully plumbed Donkey!!!


----------



## Brian Rupnow

I simply had to stop and take a few minutes out from one of my "real" jobs this morning to get a few "beauty" shots of the Donkey. My new 45 degree elbows came in from PM Research and I was able to drill and tap them last night without any mishaps occuring. The control handle for my main air/steam valve is finished and installed, and the piping to the cylinders is all completed now. The firedoor is installed. My airline enters thru the side of the base, then emerges inside the boiler, where it hooks into my main control valve. This is turning out to be one of the prettiest engines that I have built. I had it running last night, and that main control valve does a great job of controlling the speed, and the engine self starts with no problems.---And dang!!! I wish I'd thought to wipe that red lay out die off the handle in that top picture!!!!


----------



## cfellows

Dare I say that I think this is your best work yet? Very pretty engine. You'll get as much pleasure out of looking at it on the shelf as you do running it.

Chuck


----------



## ozzie46

Absolutely stunning!! Super Job!  :bow: :bow: :bow:


  Ron


----------



## ronkh

Brian,

Absolutely lovely engine both with the work that you put into it and the fine detailing. The elbows really help to "make" it and worth the wait.
Also the "boiler" was well worth the money you paid for in that lump of ali!
Fascinating and thank you for a marvelous build.
Now, where's the vid please?!!?

Kind regards,

Ron.


----------



## vcutajar

Nice one Brian and thanks for showing me your ups and downs during your build. Learned many things.

Vince


----------



## Harold Lee

WOW!!!! That is a great job Brian.... Not only did you build it but you designed it as well. You have my undying admiration...

Harold


----------



## AussieJimG

A stunning engine Brian, right down to the 45 degree elbows.

Thank you for allowing me to follow your work from start to finish. It is only on sites like HMEM
that one has the privilege of following an expert craftsman like you through the trials and
tribulations of a complete project and it both enjoyable and very instructive.

 :bow: :bow: :bow:

Jim


----------



## miner49r

Very Cool Brian. What do you plan on using for your drag line?
Alan


----------



## Maryak

Nice one Brian, :bow: :bow:

Best Regards
Bob


----------



## Brian Rupnow

I am going to have a difficult time deciding when this project is "finished". I know that I want to add a set of ashpan cleanout doors---(By the way, the ones Captain Jerry did on his donkey last week were absolutely marvelous!!) ---I MAY put a brake on it, but I'm still not sure. I will probably bolt some small superstructure to the front of it to attach the hook on the end of the end of the hoisting cable to. Right now when the engine runs, the drum rotates in "freewheel" mode but it shouldn't really, unless the clutch is engaged. I want to lay up at least a couple of layers of authentic looking "hoisting rope" on the winch drum. I would like to eventually blow it all apart and paint the base, bearing stands, and crosshead guides. I have no real desire to start another project at this point, so will probably continue to slowly make improvements to this one. I have all of the detail drawings completed except for the base, so I will probably soon post a download link so anyone wanting the plans can download them. Thanks guys, for all of the kind words and encouragement along the way.-----Brian


----------



## tel

You did good Brian - this one next?


----------



## Ken I

Brian, that is a lovely piece of work - it has such an "engineering" feel to it - I want to rush out and build one - one day - maybe - if I can get my finger out.

Ken


----------



## Brian Rupnow

Thanks Ken----Something Jerry said over on his "Donkey Post" has me thinking. Jerry was talking about an A frame boom.--I'm looking for a way to dead end my winch cable, but still be able to demonstrate the clutch mechanism----Wheels are turning------


----------



## Jared

Wow, it looks great! If you're going to do some lifting to show off the clutch, then you're gonna need a brake to show off as well.


----------



## SBWHART

Great looking engine Brian 

Stew


----------



## Jasonb

Nice little steam crane here Brian if you want a bit more work. Quite a simple boom arrangement but you can leave out the slewing gear if you want 

http://www.prestonservices.co.uk/locomotives.htm

J


----------



## Brian Rupnow

There you go fellows. If I've done this right, (I'm never sure), this should get you all 51 drawings as pdf files by clicking this download link. I give you fair warning, this is not for the faint of heart, nor the inexperienced (newby) machinist. It is a wonderfull project, and I believe the drawing details cover about 98% of what I have built. The other 2% you will have to make up as you go along. If you download this set of drawings, please give me a karma point, otherwise they are free. If you discover any horrible errors let me know. There shouldn't be any, because these drawings are the ones I built from, but design engineering is a strange business, and sometimes errors do slip through. The project is not totally finished, but I will not be creating any more drawings for whatever I do as I move foreward beyond this stage.-----Brian
http://www.mediafire.com/download.php?zmb9s8w2w11atfi


----------



## AussieJimG

A karma to you for the journey. I won't download the drawings as the project is beyond my skill level at present. But following has increased my knowledge level greatly. Thanks
Jim


----------



## Ken I

Brian Rupnow  said:
			
		

> design engineering is a strange business, and sometimes errors do slip through.



Tell me about it - I worked for a company that had been maunfacturing a particular (shockabsorber) part for over 30 years when someone discovered that a cardinal dimension was missing from the drawing - how had it been made all these years - Who Knows !

Ken


----------



## Brian Rupnow

As I said in an earlier post----I like Captain Jerry's idea about an A-Frame boom---Might go here next!!!


----------



## Don1966

Brian you are by far a great craftsman, that is a superb built and thread. I have loved reading your progress :bow: I am looking forward to your next built. You are a superb teacher.

Regards Don


----------



## ShopShoe

Brian,

Yours and Jerry's donkey projects are addictive reading. Were I to be able to build one of these (Maybe someday...), I know I would spend a lot of time running it and lifting things and all that.

I have never seen one of the full-size hoists in operation, but I have seen winches that are similar being used to assist pulling ropes to move things around. (with a team of men pulling on the ropes.) Perhaps you could make some small snatch blocks as accessories.

I don't mean to add work, I just saw it in my mind's eye and couldn't resist posting.

Congratulations again.

--ShopShoe


----------



## Ken I

Brian,
    Thanks for the free download - much appreciated - definitely worth more than one KP.

That's quite a haul of KP points you've got yourself there.

Regards,
      Ken


----------



## moconnor

Hello Brian,

When ShopShoe mentioned making snatch blocks in his last post, I remembered an article in Guy Lautard's *'The MACHINIST'S THIRD BEDSIDE READER'* about his friend Bill Fenton and the steam operated, two-drum donkey engine that he built. In the article, Guy describes in great detail (with drawings) no less than four different blocks that he dubbed "Bill Fenton's Jewelry". The donkey engine is also shown in *'A Video Visit with Guy Lautard and Bill Fenton' *  as well as both of their workshops.

http://www.lautard.com/

Guy's books are very informative and interesting reading and and I would highly recommend them to all here. He writes in a style that is unique among the usually cut and dry world of machining and model making treatises. It is quite addicting, because Guy manages to describe a project or technique in a way that makes the reader feel as if he his sitting on a stool in his shop and being told exactly how he went about the job. He can also tell a great story.

Great work Brian on the engine and the documentation. As always, very interesting to follow along with you as you design and evolve your projects. Can't wait to see what you come up with next.

Kind regards,
Mike


----------



## Brian Rupnow

Found a little spare time and a piece of scrap aluminum yesterday, to start the A-frame hoist.


----------



## vcutajar

Brian

You never rest. Thanks for the plans. I will not be downloading them as I think it's a bit above my skill level but still a karma point to you for your dedication and unselfishness.

Vince


----------



## Brian Rupnow

And some time this afternoon to finish cutting it out, profile the edges, and chase down a couple of stainless rods to become the legs. Hand bombing the radius around the edges is very finicky business, but when done right, it adds a lot to a part.


----------



## jonesie

thanks brian a karma sent your way jonesie


----------



## Brian Rupnow

And a little tad of mig welding----


----------



## Brian Rupnow

The fun just never stops around here-------------


----------



## miner49r

Looking good Brian. You are getting close to making a turret and mounting it to a rail car. 
Alan


----------



## Brian Rupnow

Things have kind of lurched to a stop here. I can't find any round 1/8" or 5/32" diameter, black, rope/cord nor twine that looks like a cable for my winch drum. The local hardware store has the perfect size and shape in a white polynylon cord, but as far as I know you can't die that stuff black. Fishing tackle doesn't come that big around (at least not 1500 miles inland where I am). I am going to call the drapery companys in town after I finish this post and ask about black sash cord. I already went to the shoe repair shop hoping they sold work boot laces by the linear foot, but no joy there. Does anybody have any suggestions?----Brian


----------



## Jasonb

Those sound a bit thick to me and would look overscale, something more like 1/16" would be more in proportion.

Why don't you use steel cable its readily available in a whole range of diameters, as an example the winch drum on the traction engine in my avitar is a similar dia and 1/16" steel cable wraps round that with no problem, just add a thimble and crimp to the end and it will look like the real thing rather than string.


http://www.tecni-cable.co.uk/Products/Galvanised-Wire-Rope-7x7-Flexible

Are you going to add any straining wires or rods to the boom as most small jibs have them.
J


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## Brian Rupnow

Never underestimate you local fabric shop!!!! They have all kinds of winch cable looking stuff, in a host of colors and diameters!!! This stuff happens to be satin, but its strong enough that I can't break it. (And if it doesn't work as winch cable, I can knit myself some unmentionables.)


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## Brian Rupnow

Aha, by God!!! Slick as a tin whistle!! Of course I have yet to replace the drill which is currently acting as the shaft for my brass pulley at the top of the boom, and organize something a bit nicer looking than that lump of steel hanging on the end of the winch cable, but I think the "winch cable" looks just right.


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## Brian Rupnow

"Are you going to add any straining wires or rods to the boom as most small jibs have them."---I really don't know what I'm going to do. The boom was just a last minute thought, inspired by Captain Jerry. It didn't require a lot of thought nor effort to build, and it does give me a way to end off the winch cable, which I hadn't figured out before. The machine was never designed to work with an A frame boom, and consequently there are no good places to run stay rods to. I may just leave it as is.


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## Captain Jerry

Brian

I like the A-frame boom (of course) but there is one thing that bothers me. In twenty five years in the construction equipment business, I never saw a boom rigidly attached at it base. To do so invites catastrophic failure as the boom will deflect under load and all of the stress is focused on that point. I realize that this design was a quick response to an impulse but don't allow anyone to stand under it. It is a hazard. 

It should be pivoted at the boom foot and supported by some kind of back stay rig. Draglines and clamshell excavators, which typically carry their boom at a low angle and subject it to high cycle loading commonly use a gantry arrangement to increase the effective angle of the backstay. I have attached a very crude diagram of a possible arrangement.

The gantry frame is pivot mounted (for the same reason as the boom) to the A-frame. The backstay is of fixed length as is the guy which transfers the load to the main frame. I realize there is no historic precedent or example of a donkey so configured but it is based on common practice. And it would look pretty cool.

Jerry


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## Ken I

Brian,
    Just a thought - some ultra flexible copper wires have multiple wound strands that look very much like steel cable - especially if the strands are tinned (or chemically blackened ?).







Check out some of the fancy speaker wires available at Hi-Fi shops.

Ken


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## Brian Rupnow

I think my Donkey may have found its permanent home!!! When a project moves off the corner of my work desk and makes it onto a shelf, thats a pretty good indication that I've worked on it enough.


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## miner49r

Brian,
Congratulations on another project well done. What's next?
Alan


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## Brian Rupnow

Alan---I don't have anything in mind right now. I have about a months engineering work lined up, and then I think I'll take the summer off. I'm burned out on machining right now anyways. Hot rod season is just about to begin, and I have a couple of young grand daughters that the wife and I will probably spend a good bit of summer with, just touring around.


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## AussieJimG

What can I say Brian except thanks for a wonderful ride that took me to places and heights that I never thought I would see. And even into a fabric shop!

I hope you come across a suitable glass case on your travels, that engine deserves it.

Jim


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## steamboatmodel

Well done Brian,
Regards,
Gerald.


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## ronkh

http://www.youtube.com/watch?feature=player_detailpage&v=OmgX5vVtByg

Is this link of any use/help?

Ron.


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