# 1.75 Minnie traction Engine



## dnalot (Aug 14, 2015)

Having recently completed a Clayton Steam Wagon I decided I like big projects that take some time to complete. While building the Clayton I acquired the original book on the Minnie designed by Leonard C. Mason in 1969 in 1 scale. And a set of drawings in metric by Arthur Droves. The metric drawings were very helpful in that they were very detailed and had exploded views of the parts.

I decided on the scale based on the limits of my machines and a piece of 4.5 copper tube I had in stock. With an expected weight of 90 pounds its also the largest I can lift.

Step one, draw all the parts to the new scale using Draftsight. So that took a while but I now fully understand the plan. As I made my drawings I acquired most of the materials I would be needing for the Minnie. 
The first thing I did was build a fixture to hold the boiler and a rotating platform for it to sit on. The fixture will come in handy for holding the engine during assembly but first it will be used to mount the boiler to the mill for a lot of drilling. 

The boiler is the biggest expense and probably the most difficult part of the build so thats where I will start. Its not easy to heat up 30 pounds of copper to 1180 degrees for silver soldering. I love pounding on copper. It is amazing how easily it forms and how close to the final shape & fit you can get by hand. Everything else about copper sucks.

I am planning on an operating pressure of 80 Lbs so I tested the boiler at 200 PSI.  I would like to say I had no leaks but you know that never happens. I had a few and fixed them before moving on to the next step. 

Overall length 15.5 width 4.75 height 8.25 Weight 30 pounds. Material; Copper

Well its a start. 

Mark T


----------



## Herbiev (Aug 14, 2015)

Wow !  Very impressive work. Will be following with great interest. is that a pneumatic scaler you are using as a riveting gun?


----------



## dnalot (Aug 14, 2015)

> is that a pneumatic scaler you are using as a riveting gun?



Hi

I am a licenced Aircraft mechanic and that is my short stroke riveting gun, been using it since 1974. 

Mark T


----------



## bmac2 (Aug 14, 2015)

Hi Mark 
Great work Ive got my chair pulled up as and the kettle on. I like those little spring clamps on the water jacket I dont think Ive seen them before. Being your short stroke gun is from 1974 would it be safe to assume that it isnt stamped Made in China?


----------



## Jasonb (Aug 15, 2015)

You are off to a good start, did I see you have fitted a clack bush inplace of the boiler mounted pump which is a wise thing.

J


----------



## dnalot (Aug 15, 2015)

> I like those little spring clamps on the water jacket I dont think Ive seen them before



Do a google image search for "cleco" and you will find a wide variety. The are used by aircraft sheetmetal workers. They are small but very strong. McMaster-Carr has a few.

Mark T


----------



## dnalot (Aug 15, 2015)

> I see you have fitted a clack bush inplace of the boiler mounted pump



I wanted to mount the pump lower so it would not have to lift water to get primed. 

Mark T


----------



## dnalot (Aug 15, 2015)

> Being your short stroke gun is from 1974 would it be safe to assume that it isnt stamped Made in China?



Made in England actually. 

Mark T


----------



## dnalot (Aug 24, 2015)

Next up cutting the gears. Never tried that so I expect it to be challenging. 

The original model called for gears made of steel. I plan to use as little steel as possible to avoid rust over the long term. The smaller gears I will make from silicon bronze cut from round bar stock. The three larger gears I will need to cast planks for. I have salvage Aluminum Bronze for that. Thirteen gears in all. From 1 12 Tooth to 6.8 82T. Five of the gears are for an added feature the original model lacked, a differential. 

Using my CNC router I made a indexing disk that I will use for all my indexing needs for this model. I designed and built a fixture for cutting all of the gears. With a spread in diameter from 1 6.8 and several different hub diameters the fixture turned out to be a bit of work. The mandrels will also be used to turn the gear blanks to the correct diameter. The round blob next to the indexing ring on the fixture is a 6 pound lead half round. It takes out most of the fixtures vibration and ringing. The pitch for the gears is 12, the depth of the cut is .1853. I didnt think my little SX3 mill could handle that in one pass but it did very well. I recently upgraded its lead screws with ACME Ultra smooth threaded rod and self-adjusting nuts in anticipation of this job. 

Link to mill upgrade 

http://www.homemodelenginemachinist.com/showthread.php?t=24448



Cutting the first gear was a lot of fun. After that it was just a lot of repetitious work. I cut at a rate of about 40 teeth per hour. With my home made fixture it took longer to set up a cut than it did to make the cut. I only needed to cut 367 teeth so I took my time. To sum it up, the hardest part of making gears is paying for the cutters.

The steering worm gear set I purchased.

Mark T


----------



## cr4k3r (Aug 24, 2015)

Very nice indeed sir, the gears are well finished and cut. I will follow this to the end, your work is beautifull. Keep the pic comming.


----------



## dnalot (Sep 14, 2015)

With the gears cut I am now able to measure them and mark out the mounting points for the four shafts on the horn plates. The horn plates and specter plates are made of steel. The shafts are made from drill rod. I made several modifications to the plan here. I opened up the hole for the crank shaft so the crank could be removed without taking the horn plates off. And I joined the bushings for the drive axle with a tube. The new axle housing will hold the bushings in alignment and help tie the horn plates square to one another. I also made the Specter plates with formed edges to add a little style. (The axle housing and the bushing supporting the flywheel have bronze bushings pressed in, the other shafts run in brass bushings)

I used a fixture to hold the boiler square while milling the stays that would be the mounting points for the Horn Plates. And I used double back tape to hold the horn plates together for shaping and drilling to assure the proper alignment of the holes. The method paid off with great results, when assembled, everything lined up nicely and the gears meshed very well. It only took a little filing on a few teeth to get everything turning smoothly and there is surprisingly little backlash in the gear train. I added a differential, requiring 5 additional spur gears. Its a simple setup but works well. 

With the Horn Plates installed and the gears turning smoothly there are now multiple ways to proceed with the build. I have been working on the side making Smoke Box parts so I think I will turn my full attention to completing the front end next. 

Mark T


----------



## bazmak (Sep 14, 2015)

Beautiful,i am very impressed and will follow with great interest.
You say you have tested the boiler to 2.5 working pressure,i assume hydraulic
Will you be getting it retested with certification ??? regards barry


----------



## dnalot (Sep 16, 2015)

> Will you be getting it retested with certification



Probably not. I will fire it up once or twice and put it on a shelf to look at after. It is smaller than the threshold for required inspection in my State. 

Mark T


----------



## RonGinger (Sep 16, 2015)

Very interesting differential- I did almost exactly the same thing with my MINNIE. I enlarged mine slightly, to 125% of the drawings if I remember correctly. My first attempt at the differential had trouble with the shaft that runs through the big 'bull' gear. Because the gear was relatively thin the shaft didn't get enough support. I made a second version with a couple pins inserted and gears that rode on the pins. It was much more successful. I have never hauled anything with mine, simply ran it on air and only let it move a couple feet.

I never did post any photos of the differential, but here is a link to a few photos of my MINNEY- note I mis-spelled the name because I didn't really follow the plan completely. http://plsntcov.8m.com/minnie.htm


----------



## dnalot (Sep 17, 2015)

> Because the gear was relatively thin the shaft didn't get enough support.



I had a similar problem with stability of the drive sprocket when I built the Clayton Power Wagon. For this build I was very careful to fit the bull gear closely to the axle shaft. Then the bull gear rides between two gears that were silver soldered to their axles and then faced on the lathe. The left gear being mated to the long axle and the right one being mated to the short hub/brake drum. The bull gear tracks dead on square and turns easily.

I could not get your link to work but with a little searching found the page. This link should work   http://plsntcov.8m.com/minnie.htm

That is a very nice looking model.

Mark T


----------



## ddmckee54 (Sep 17, 2015)

If you look at the properties of both links, you'll see why the first one doesn't work.

The first link is "http://http//plsntcov.8m.com/..."
The second link is "http://plsntcov.8m.cov/..."

You just can't trust computers, I swear they all have dyslexic keyboards.

Don


----------



## dnalot (Oct 3, 2015)

I have had to take a break due to surgery but at long last Im back in my shop. Boy I sure missed fiddling about in my shop, it sucks to get old.

I had a 4 long piece of copper tube left over so I will be using that for the smoke box. The base for the smoke stack is a very odd shape and I elected to use the lost foam casting method. I roughed out the shape using sandpaper and then buried the foam part in green sand for casting. The part was cast from old cartridge brass that is not very good for casting. I did get a suitable lump of metal for my efforts. A little sanding with the drum sander and it fit snugly to the smoke box. Next I chucked the part in the lathe to do the machine work.  From there on it was hand sanding and filing to get the final shape, and a bit of buffing to make it sparkle.

The door and its mounting ring jam were turned from a single cast piece of stock. After silver soldering the hinge bits, I nickel plated the ring. After fiddling about getting everything to line up straight and square I riveted the smoke box parts together. 

Next I fabricated the perch for the front axle. This was a simple brass fabrication job with a turned bronze part to receive the yoke. After riveting the assembly to the smoke box I painted the smoke box with heat resistant paint. The paint on the firebox and smoke box are the only parts I plan to paint. Everything else will be left metal. Steel parts will be ether blackened (shiny or matt) or nickel plated (shiny or matt) 

The front axle yoke I made from steel. I have deviated from the plan here, providing for a thrust bearing, and giving the part more of a cast look. I also provided a spring system to stabilize the axle.  Both the axle and the yoke have been nickel plated. 

I am now working on the wheel hubs and have them mostly completed. I will probably leave the rest of the wheel assembly to later as Im still not decided on how I will go about making the rims.  I have resisted using any aluminum on the model but at this point Im thinking a cast aluminum rim would be cheap and easy. If I go with aluminum I would anodize the part and then die them black. I have made the patterns for casting but Im thinking I might try making a tool for rolling the rims from brass flat stock.

Mark T


----------



## Twizseven (Oct 3, 2015)

Mark,

That looks very nice.  Out of interest what paint are you using.  I assume that if you intend to fire the boiler and run on steam then you have used a heatproof paint.  I have a 1" scale Minnie I bought nearly complete but it has been painted in cellulose car paint.  I reckon the second the boiler gets fired the paint will bubble and peel off.  I either have to decide never to fire it or to strip down completely, remove the paint and repaint in some form of heatproof paint.

Colin


----------



## dnalot (Oct 3, 2015)

> Out of interest what paint are you using



The painted parts are made of copper so I used ferric chloride to etch the surface and then painted with a paint intended for painting an engine block that was rated to 500 degrees and is oil resistant. I hope it will work out OK.

Mark


----------



## Twizseven (Oct 7, 2015)

Mark,

Thanks for info.  It will be some time before I get around to it.

Colin


----------



## chucketn (Oct 7, 2015)

Just got caught up with this thread. Nice work, Mark. Please elaborate on the roller for the wheel rim. Could it roll mild steel for a flywheel rim? Plans?

Chuck


----------



## dnalot (Oct 8, 2015)

> Please elaborate on the roller for the wheel rim. Could it roll mild steel for a flywheel rim? Plans?



I saw your post about rollers first and I posted a photo of a roller there. I think I will try and make one in the near future. I have to stay away from welding smoke for at least another 6 weeks. I need to roll 10.5" Dia. by 2.5" wide by .25" steel or brass. 

Mark


----------



## Jasonb (Oct 9, 2015)

You don't need to make the rim that thick, one of the problems with scaling up the Minnie which was a bit chunky to start with. There are plenty of 2" model traction engines running with the rims from 1/8" material and the tees welded in, they would have 12-13" dia rear wheels.


----------



## gus (Oct 9, 2015)

Hi Mark,

Your post on the boiler is  very useful for me as I have been wanting to build such boilers. Due the complexity,I gave up. Would have to invest in brazing torch. The Mapp Gas Torches is not exacty  for very small boilers.


----------



## dnalot (Oct 9, 2015)

> You don't need to make the rim that thick



Thanks for the info. I think I will do as you suggest. 

Mark


----------



## dnalot (Oct 9, 2015)

Hi Gus



> Would have to invest in brazing torch



It took a lot of heat to bring so much copper up to temp. I used a ceramic insulating blanket and fire bricks to help hold in the heat. The biggest problem I had was chasing the few leaks I had. It was like a game of "wack -a-mole". I used more gas chasing the leaks than I did the first go. You need to keep all of your openings for fittings OPEN during the soldering to help keep inside and outside pressure equil. 

Mark


----------



## gus (Oct 10, 2015)

Now I see good reason why my mini 1 1/2''O.D. -----------2'' O.D. Copper boliers weren't brazed as good as yours. Will put together a DIY Brazing Hearth sometime later. Plan to buy Oxy- Acet. Equipment. Thanks for showing the way.


----------



## dnalot (Oct 27, 2015)

Hi

I have completed the rear axle assembly and the tender. 

The rear wheel hubs I made from brass flat stock, soldered together. The drum for the wench I turned from aluminum. 

The tender was made from brass sheet. The sides were fairly easy to form but the heat from annealing warped the sides some and I had to fight with that moving forward. I was a little apprehensive about driving the rivets with a rivet gun do to the thin stock I was working with. As it turned out the rivet gun worked out just fine. 

The rolled edging at the top of the tub I made from .25 half round. I used silver solder to join the parts together and then used soft solder to attach the edging to the tub. At the same time I soldered all the joints of the water tank to seal them. 

I still have to drill some holes for mounting several parts and the bulkhead that forms the coal box. After I do that I will do the final sanding and polishing of the tub.


----------



## dnalot (Nov 18, 2015)

With the Tender mostly completed I turned to some of the details that connect to the tender. 

First up was the roller guides for the cable. The rollers made from drill rod actually work.

Next I made the jack screw and clamping band for the brake. The band was salvaged from banding used to hold band saw blade material in a roll. It was a perfect size and it was springy.

I followed that with the quadrant for the control rod that will but the engine in forward, neutral or reverse. It still needs to have notches cut into it but that will have to wait until I have the engine built. 

I altered the plan by putting the valve for the return water line from the water pump inside the water tank. I soldered the valve to the bottom of the floor plate just below the steering wheel. The valve can be turned by an extension that puts a control wheel near the top edge of the tender. 

The final detail of the tender is a bulkhead that provides a bin for coal. 

With the tenders details completed I went ahead and put the final finish to it as I dont think it will be separated from the model again. Most of the parts I plan to let age naturally, but the tender looked rather bad after soldering and cleaning around the rivets proved to be difficult. So after sanding and burnishing I used some acid and burnt oil to age it a little and then hand rubbed it with lanolin and light oil. 

I have also completed the steering system. I bought the worm gears as Im not up to that challenge yet. I did make a change to the original plan when making the drum. I made it in two parts so that when the chains are installed I can rotate the two halves to adjust the slack in the chain before locking the drum in place with a set screw.

Well I cant put it off any longer so next up is the wheels. The hubs are done so its time to make the parts for the rims and the spokes. And then I need to make an assembly jig for assembly. Unfortunately my wife wants some work done in her kitchen so I may not get to start for a few weeks.   

Mark T


----------



## dnalot (Nov 25, 2015)

Hi

I'm back in my shop and its time to make some wheels.

The first step in building the wheels is/was to make a tool for rolling the rims. The tool is not my design, I saw an example and scaled it down for my use. The tool was made from bits and pieces around the shop and took me about 5 hours to make. Rolling the two rims took less than 10 minute and was almost effortless. I expected some slip of the driving roller but that didnt happen.  The rim was rolled from a 36 strip of half hard brass 2.5 inches wide by .125 inches thick.  That will allow for about 1.25 to be trimmed off the ends of the rolled ring. I think the lower limit on size will be about 3 diameter rings. The one in the photo is about 11 in diameter.  The photo showing the parts is missing the two 3/8-24 bolts that are used to jack the lower rollers up towards the work.

With the rims rolled I am now making a fixture for turning the inner flanges of the rims. It will also serve as an assembly fixture and will work on both the lathe and the mill.


----------



## dnalot (Dec 19, 2015)

Got a little more time in the shop and have made a little more progress.

After rolling the rims I rough cut the parts needed to make the flange that the outer end of the spokes mount to. Each ring was made up by silver soldering 4 pieces together. Four rings are required for the two rear wheels, I mounted all four of the rough cut rings to a fixture plate adapter on the lathes flat wheel, and turned them as a group. 

With that completed the next step was to silver solder the flanges to the rims. I then sand blasted the rim assembly and mounted the rims to the fixture plate and mounted that to an indexer on my milling machine. I needed to drill the holes for mounting the traction cleats to the rim, but the wheel was too large to be drilled with the mill so I fashioned a drilling jig and drilled the holes with a hand drill. There are 72 cleats for both wheels and it was boring making so many parts. It was fun driving the rivets however and the rim really started to look like something with the cleats mounted.

I then mounted the rim assembly and the wheel hub to the fixture plate and measured for the spokes. Each wheel has 16 spokes and each had to be made and bent to fit properly to the wheel. I thought this part was going to be a slow process but fitting the spokes turned out to be quick and simple to do. At this point I deviated from the plan as the plan called for soldering the spoke to the center hub. My parts fit very tight so I simply drilled the hub end of the spoke for a pin, and used loctite to glue in the pin. I then made a custom bucking bar for driving the rivets that secure the spokes to the rim assembly. And again the fun part was driving the rivets. 

The wheels turned out surprisingly round and they turn true. The last driven rivet wasnt even cold before I had the new wheels mounted. The rear wheels measure 11.25" in diameter. I have now leveled the engine and measured for the center of the front axle to the ground. With that dimension its now time to start building the front wheels. 

Mark T


----------



## 10K Pete (Dec 19, 2015)

That is one beautiful engine!! I'm in awe of your workmanship in building
this. It will be very exciting to see it under steam!

Pete


----------



## Herbiev (Dec 20, 2015)

Thats a very classy looking machine. Looking forward to seeing it in action


----------



## dnalot (Dec 22, 2015)

Hi

Thanks for the kind words guys. Yesterday I made the rims for the front wheels. Today is another day at the doctor's office but I hope to have the engine sitting on its wheels by the weekend. I'm chomping at the bit, wanting to get started on the engine. "Saved the best for last"

And I would like to give Space-X two thumbs up on the landing of their booster rocket yesterday. 

Mark T


----------



## dnalot (Dec 27, 2015)

Hi

The front wheels are a simplified version of the rear wheels and I used the same fixture and procedure as before. I have aged the wheels to a nice chocolate brown with dark red highlights. After aging I soaked them in oil and wiped them down. After the solvents dry off I will rub the wheels down with a soft cloth to bring the shine back and a few more highlights.

And as you can see I have started the flywheel. The rough lathe work is completed and the next step is to mount it to a turntable for cutting the six spokes on the mill.

Mark T


----------



## 10K Pete (Dec 27, 2015)

Aww Mark, those are beautiful wheels! Coloring is just perfect.

Pete


----------



## idahoan (Dec 27, 2015)

Beautiful work Mark!

I'm just catching up here, and am in awe at the fine craftsmanship you are putting into this project.

Dave


----------



## Jasonb (Dec 28, 2015)

Just caught up with teh last two updates and the wheels are looking good.

I notice that you said you "leveled " the engine, it should actually slope down towards the back. With the boiler level on teh 1" the front wheels should be 3/32 below the rears so about 5/32" on yours.


----------



## dnalot (Dec 29, 2015)

Hi



> I notice that you said you "leveled " the engine, it should actually slope down towards the back. With the boiler level on teh 1" the front wheels should be 3/32 below the rears so about 5/32" on yours.



I guess I should have said I adjusted the engines attitude. I have the barrel of the boiler sloping back to the rear by .5 degrees. That comes out to 3/16" higher at the front axle than the back.

10K Pete, where in washington is Nordland? Is it a town or just a post office. 

Thanks for your comments guys. Your fueling my desire to work harder. Today I start cutting spokes into the cast iron flywheel. I bought the 8" x 1.5" round of iron from McMaster Carr. It is the nicest cutting cast iron I have encountered.

Mark T


----------



## 10K Pete (Dec 29, 2015)

Mark,
Nordland is on Marrowstone Island inside Mystery Bay. We're about 5 miles
ESE of Port Townsend, across the bay. We have a post office, general store and a boat canvas maker right in downtown. Just north a few hundred
yards is Johnsonville with the oyster company and construction company.
The only reason you can't miss Nordland driving by is that if you go fast
enough to miss it when you blink, you'll run off the road into the bay!
Nice small and quiet.

Pete


----------



## dnalot (Jan 1, 2016)

Hi

The flywheel was cut from a 1.5 by 8 round of cast Iron I purchased from McMaster Carr. The material was very nice cutting without any hard spots. It took a few hours to rough out the shape on the lathe and a quite a few hours doing the mill work. Very little filing was needed and the final texture was added by sandblasting the spokes and hub. After sandblasting the part was placed in the bucket for Parkerizing. After that the flywheel was mounted to a shaft and turned to its final diameter and the rim sanded smooth.  

Mark T


----------



## dnalot (Jan 4, 2016)

Hi

Time to make the crankshaft. On my last two engines I turned the crank one piece. This Time I have opted to assemble the crankshaft and silver solder the parts together. My camera had a low battery so some of the photos were not usable. Sorry about that. 

The shaft was made from .5, 8 long drill rod. And the webs were cut from 12L14 steel. I fit the shaft to the web with a close fit. After that I removed about .003 from the shaft where the web will ride, leaving a small shoulder to hold the shaft centered in the hole. A .125 hole was then drilled through the edge of the web at each joint for feeding the solder into the cavity between the shaft and the web. I mounted the shaft to v blocks to support the shaft during soldering and clamped the v blocks to a straight piece of heavy metal. The main shaft runs through the webs during soldering but gets cut away afterward. After soldering I let the assembly cool completely before I took it out of the "v" blocks and cut away the unwanted section of rod between the webs. A little filing and sanding and a quick dip in the Parkerizing bucket and the part was done. 

I placed the crank in the lathe to check for straightness. The crankshaft is 8 long and I had a deviation of .0036 at the midpoint. I slipped the eccentrics and the shift gears onto the shaft and fit the assembly to the engine. It turns butter smooth and the flywheel has no wobble. Im a happy camper.


----------



## dnalot (Jan 20, 2016)

Hi

The engines cylinder assembly was cut from a 3x3x4 block of brass. The original model was made from a casting that included the saddle. Mine required the saddle to be made separately and silver soldered to the cylinder block. And like the original model the cylinder sleeve was soft soldered into the block. The most difficult operation was fitting the unit to the boiler to be in line with the crank, at the proper height, plumb, and square to the barrel of the boiler. To keep from getting chips into the boiler while I drilled and taped the holes for mounting I pressurized the boiler to about 15 Lbs with air. At this point all of the holes have been drilled and tapped, all of the steam passages have been milled or drilled and the stuffing boxes are complete. The bore is 1.187 and the stroke is 1.75. Having 2 power strokes with each revolution yields about 50CC displacement.

Next to do is producing all the motion parts. 

Mark T


----------



## robj.brown (Jan 20, 2016)

Wow nice work


----------



## dnalot (Feb 5, 2016)

Hi

Before moving on to the motion parts I aged the completed components of the engine and mounted it permanently to the boiler. Followed by mounting the motion plate and its saddle before pressure testing.

With that done the boiler was wrapped with a brass sheet insulated with .125 of ceramic insulation. The wrap is held in place with three nickel plated straps.

There are three stuffing boxes on this engine. An 1/8 a 3/16 and a 1/4. I am using O-rings for seals that are 1/16 in diameter (actual .070). The rods passing through them are polished S.S. The well these seals sit in are very easy to cut and the system seals very well without binding. I start by reaming the hole for the shaft .001 over and then use an end mill .125 larger in diameter than the shaft to cut the recess for the O-ring.

I started with the piston & rod and the cross slide. The piston is brass and the cross slide is fabricated from brass and bronze. Once I had these parts installed and moving smoothly I measured for the connecting rod and made it from a 1/2 square piece of steel.  The strap is made of steel as well and is located in place by a tapered pin. Bushings are made from PTFE impregnated material. I must have located the engine on the boiler nice and square because the connecting rod when installed moves smoothly. The hole in the spectacle plate was a little off so not everything went to plan.


I now have a good start on the motion parts for the steam box valve. Most all the control linkage parts are made and have been fitted to the model. After I post this note Im off to make the valve. On my next post I hope to be able to post a video of the first run on air.


----------



## Herbiev (Feb 5, 2016)

Looking great so far. Keep the pics coming.


----------



## dnalot (Mar 5, 2016)

Hi

The stack required a tapered tube. I didnt think I could roll a smooth looking tube so I Made a tapered mandrel and used it to stretch a length of copper tubing. The base of the stack and the crown I cast using the lost foam method. After silver soldering the parts together I left the part as is as the heat gave a very nice finish. 

Mark


----------



## dnalot (Mar 5, 2016)

The control rods for the steam chest valve were made from brass in several separate parts and then silver soldered together. With those parts in place the engine was ready to run. So I ran it for the first time.. Sweet. She purrs like a kitten. Smooth and powerful and the reversing mechanism works well at most any speed. With the engine mounted directly to the boiler the response time to changes in the regulator were crisp.


----------



## dnalot (Mar 5, 2016)

The sight glass I made from some modified plumbing parts. It doesn't' show in the photos, but there is a pipe plug in the end opposite the valve for inserting the glass tube. I will replace the T handle on the valve with a wheel. Simple cheap and it works well..


----------



## dnalot (Mar 5, 2016)

The water pump is one area that I have deviated from the plan. It had been reported that the original pump did not work well. The original was mounted on the boiler well above the water tank. I relocated the pump to the side of the right horn plate with the pickup tube level with the bottom of the water tank. The pump is a complete redesign. Also changed is the location of the return line valve. The original had it mounted on the outside of the water tank. I have mounted it inside the tank. The pump is working and will pump a lot of water quickly and has no problem forcing water into the pressurized boiler.


----------



## 10K Pete (Mar 5, 2016)

Great engine, Mark. I don't think I ever thought about how many gears are in
one of those machines. Amazing work. Can't wait for the video!!

Pete


----------



## dnalot (Mar 5, 2016)

Every steam boiler needs a whistle. So I crammed one in.


----------



## dnalot (Mar 7, 2016)

Hi

The oil pump on the original model looked like it was tacked on as an afterthought to the rear of the motors head. The arm that drives the ratchet was slaved to the rod that drives the steam chest valve. 

I have relocated the oil pump to the specter plate and the rod that drives the pump is now driven by the water pumps eccentric. The reservoir on the original was square mine is round and the internal pump is of a different design. The eccentric that drives the pumps piston is turned by a ratcheting action. The ratchet is accomplished with a one way bearing. It takes from 10 to 20 revolutions of the crankshaft to cycle the pump one revolution, depending on the hole you pin the arm to. The pumps piston is .09375 with slightly more travel. There is a check valve at each end of the copper line to prevent steam pressure from escaping.


----------



## Mark Rand (Mar 8, 2016)

Automatic oil pumps, when fitted, were normally rectangular and were often mounted off a bracket on the back of the cylinder and worked by the valve rod.

I've got a picture in front of me of Alchin's 7NHP Royal Chester showing that she had one like that when delivered from the factory. 

Having said that, one on the spectacle plate would be a bloody sight easier for the driver to reach in the morning for filling it up.


PS. Thanks for the wonderful write up. I've got a set of 1" Minnie bits waiting for me to get started on them and your work is a great encouragement.

Regards
Mark


----------



## dnalot (Mar 9, 2016)

> Automatic oil pumps, when fitted, were normally rectangular and were often mounted off a bracket on the back of the cylinder and worked by the valve rod.



Good to know. Thanks for your comments.. It has been a rewarding project, so don't let your bits go to waste. 

Mark T


----------



## dnalot (Mar 19, 2016)

This is almost the end of this thread. I have but one thing to do before declaring this project completed. As you can see the chain for steering is way too big. The chain I originally used was the correct size but had no strength and broke easily. I ordered a replacement but it will be about 10 days before I get it. After I replace the chain I will stage the model for photos and a video and post them.

The past few weeks my camera has not been working well and I have now replaced it. Unfortunately, I have lost many of the details of how some parts were made. In this post I am showing the 50 feet of cable spooled onto the drum, a guard for the gears made from .020 brass and the ash bin assembly installed. 

Mark T


----------



## dnalot (Mar 30, 2016)

Hi

Well it's been a fun build but the model is now completed. I have posted a few final photos and a short video in the completed projects section. Here is a link

http://www.homemodelenginemachinist.com/showthread.php?p=279090#post279090

Mark T


----------



## dnalot (Apr 27, 2021)

The link in the post number 57 is dead. here is one that works 1.75" Minnie Traction Engine

Mark T


----------



## Tug40 (Apr 27, 2021)

I just looked at this thread for the first time today.
In post #1 i saw what appeared to be cleco pliers & lo & behold actual clecos.
Haven’t seen those since working for Lockheed Aircraft in the late 60s.
Went to the garage, looked in pliers drawer & yup, I still have a pair.
Small world.


----------



## dnalot (Apr 27, 2021)

Tug40 said:


> In post #1 i saw what appeared to be cleco pliers & lo & behold actual clecos.



Yup still have them and still use them. And I still have my safety wire pliers. Spent many years working as a licensed A&P mechanic before switching to marine mechanic where I could make good money. Ended up owning and operating a small boat manufacturing company. (both the boats and company were small)

Mark T


----------



## ShopShoe (Apr 28, 2021)

dnalot,

I've been following along and I have to say that I like your traction engine very much. I have enjoyed the thread and I like the details you have managed to add to the engine.

I don't remember if you ever talked about paint, but I have to say I like it as it is and the metals and finishes you have used look very good as they are.

Congratulations and thank you again for posting this project.


--ShopShoe


----------



## dnalot (Apr 28, 2021)

ShopShoe said:


> I don't remember if you ever talked about paint,



I hate paint and seldom use it. I did use some high heat paint on this model. I prefer to use natural textures and aging of the metals

Mark T


----------

