# Elmer’s #5 Geared Engine . . . maybe



## bmac2 (Jun 13, 2018)

Emler’s geared engine has always intrigued me mostly because it’s such an odd design, but with the cost of that ring gear here in Canada is around $75.00 so I just couldn’t justify it to myself.







Then while cleaning up the workbench I rediscovered my “drill grave yard bin” and in there is a bunch of internal ring gears.






This started me thinking that the ring gear in the plans shouldn’t be carved in stone but more a matter of geometry and picked out a slim 42 tooth gear I think came from a Ryobi. I hated that drill, horrible chuck, weak batteries and a garbage charger but I thought this gear looks promising. With the smaller gear as long as it’s centred along the same path as the original design it should work. All this will mean is a shorter stroke and rethinking of the gear arm.





The weather forecast for the weekend was somewhere between “horrible” and “hide under the stairs” so it looked good for some shop time. I decided to start with the cylinder and valve chest that way if the whole thing goes south I’ll just build something else using a “M” type cylinder. Sorry I didn’t think to start taking pictures until I almost had the cylinder and heads finished. For the most part cylinder is just straight turning; setup offset in the 4 jaw, drilled and reamed it then rounded the ends.






Then a little drilling and tapping for the steam chest and heads.









Milled out the steam ports then flipped it on end to mill a small flat spot before drilling the steam passage.












I find there is not much more nerve wracking than a 1/16” end mill. No matter how careful I am I’m always waiting to hear that little “tink” sound they make when they break.

I know. I know I’m using a drill chuck for milling but I don’t have a collet that fits this end mill and I REALLY don’t think I have to worry about side load.

I had to mark the faces that get milled off. Somehow looking at the plans I had a devil of a time getting my head around it.


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## bmac2 (Jun 13, 2018)

Set up the piece for the steam chest in the 4 jaw and turned the small (everything on this thing is small) rounded end then flipped it, re-indicated it and turned the hub for the packing nut.





The 1/16” hole for the valve rod goes to where it almost breaks through so I like to setup a dial indicator on the tail stock screw and crossed my fingers before drilling then milled out the valve opening.


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## bmac2 (Jun 13, 2018)

For the cover and valve plates I picked up some K&S 1/16” by 5/8” brass from the hobby shop. After drilling the steam holes(?) in the valve plate I stacked the 3 pieces of the chest before drilling the 4 mounting holes to assure alignment.










The valve is really just straight forward milling and not difficult at all to make . . . . . it’s just so damn small.


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## bmac2 (Jun 13, 2018)

Mmmm small things. It was time for that valve rod. This thing is TINY!
I’ve made one of these before for the Oscillating Cylinder Engine and found it very frustrating. It’s just too long and skinny.








This time I thought I’d try something different and build it up starting with some 3/32” stainless rod (K&S again). Turned 5/16” down to the 1/16” diameter and rounded the end with a file.






Then brought it out just enough to take it down to .086 and threaded the required 9/32” #2-56.









After that it was over to the bench to use my “precision part off tool” and that part of it is done.


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## bmac2 (Jun 13, 2018)

For the head end I just milled the flats in a piece to 3/16” rod then indicated and drilled the 1/16” hole for the pin.











Then back to the lathe and drilled a 3/32” hole in it and parted it off. Whenever my wife goes to the Dollar Store I always end up dropping something into the basket and on one of these trips I picked up one of those magnetic pickups. You know the ones that look like a car antenna. I found that if I put it in the tail stock chuck it will catch most small parts I part off. Better than using it to sweep back and forth under the bench to find it.






Back on the bench theirs no load on this part so I just used Loctite to hold it tougher. That was much better. It took less than an hour to make and with no stress and frustration. The rod is over sized (.0938” not .086”) but to me all that means is that I have to drill the packing nut for the inboard head 3/32” instead of #41. . For the valve nut I just ground down a #2-56 nut and dropped it into place.


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## bmac2 (Jun 13, 2018)

I needed some ¼” Hex for the two packing nuts and I don’t have any because I never buy it, but I do have these.






I saw this somewhere on the internet and I’ve used it a lot over the years. It’s just a piece of Hex stock with a .375 hole reamed through it and a set screw. I just insert a piece of 3/8” stock, set your depth of cut, mill, rotate, rinse and repeat. 
All the hex stock I could ask for.


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## TonyM (Jun 13, 2018)

The magnet and the hex bar are a couple of great tips I had not thought of. Thanks.


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## Rudy (Jun 13, 2018)

Thanks for sharing. Very inspiring write up. And I also love that hex making device.
Rudy


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## marioserafica (Jun 13, 2018)

!!!!!!     bello !


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## a41capt (Jun 13, 2018)

Love the magnet and hex nut tip!  I’m looking forward to seeing how your gear geometry works out.

Following with much interest!

John W


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## kwoodhands (Jun 13, 2018)

bmac2 said:


> Emler’s geared engine has always intrigued me mostly because it’s such an odd design, but with the cost of that ring gear here in Canada is around $75.00 so I just couldn’t justify it to myself.
> 
> View attachment 102029
> 
> ...




Your end mill has a 1/4" shank which is not common for the holders. Make a holder from scrap round 1018 or what ever you have . Bore the hole slightly less than .250. Then ream the hole to .251. Turn the outside of the blank to fit an endmill holder you do have, I used 3/4" because I rarely use that holder. Turn the work to .749.  Mill a flat for the set screw on the holder, drill and tap for a setscrew for the 1/4" endmill. Much better than using a drill chuck. 
The holder will have less runout than most drill chucks. You need as close to no runout as possible with tiny endmills.

mike


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## bmac2 (Jun 14, 2018)

Thanks guys. I wish I could remember where I saw that trick for using a piece of hex stock I would like to buy that man a beverage. There fast and easy to make, setup in seconds, and they work great.

Hi Mike

I am in total agreement with you on drill chuck runout. If you look at the steam passages in the 6th picture down they’re very ragged. The cutter is sharp but the chuck . . . well it’s a chuck. The end mill was given to me and though I call it my “1/16 in” end mill it’s actually metric and my metric tooling is very limited.

I was going to get a start on the front and rear bearings tonight after work but one of the axis displays has packed it in (again) on my DRO. I’m starting to think that when I built it point to point wiring may not have been the best way to go.

Buy hey, point to point wiring 4 micro controllers, 4 displays, 2 voltage regulators and 3 mini USB interfaces crammed into little box that’s subject to vibration . . . . What could go wrong with that?

It’s probably just another broken wire.


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## stragenmitsuko (Jun 14, 2018)

bmac2 said:


> Emler’s geared engine has always intrigued me



Me to , it's been on my to do list for ages , and I  also saved some cordless drill gears just for that purpose .

Another good source for ring gears are bicyle hubs . The 5 & 7 speeds have 3 and  4 planetary gear sets of various dimensions . 

Pat


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## bmac2 (Jun 17, 2018)

Ok this is the boring stuff so I’ll keep it short. Spent a couple of nights Fritzing (Open source PCB software) a board for the DRO and printed it out on Friday . . . . Just thought of something, when I retire I’m going to have to buy my own laser printer . . . crap.





Got the board etched and drilled but I have a couple of jumpers that run under the Mini Pro’s so I needed some sort of spacer. After a bit I started wondering if my wife had ever done any bead work. Sure enough scored some nice little glass beads. I even got to pick them out so I could color code the pins.









While it was gutted and spread over the bench I redid the 3.3 volt supply with better filtering. A little bit of noise can raise havoc with iGaging scales. Spent today crimping way too many of those little 2.5mm Dupont connectors but it’s buttoned up and running more stable than it was so enough of this. Tomorrow I can get back to making chips.


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## stragenmitsuko (Jun 17, 2018)

From a geared elmer's to a dro to a pcb .... you've lost me  

Where do I find more info on the dro project ? 
Looks interesting for sure .


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## aka9950202 (Jun 17, 2018)

The DRO on my Mini-Mill is one by Yuri's toys. A Google search wwill find it for you. Yuri supplied the controller. The scales are purchased from any suitable source and the display unit is a tablet or phone.  It may seem complex but following the instructions got mine working like a champ. The features that the tablet provide like center finding, hole patterns to name a few are only equalled by far more expensive DRO units.

Cheers
Andrew in Melbourne


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## bmac2 (Jun 17, 2018)

Andrew has it spot on. Yuri did all the hard work and has a ton of great information on this page http://www.yuriystoys.com/. I found the stock iGaging displays hard to read unless I was straight on and had the lights adjusted to avoid glare. My original plan was to pick up an old tablet and run Youi’s full meal deal. But for some reason people on Kijiji think that a 5 year old tablet with a worn out battery is worth 70 to 80% of the original purchase price. All mine does is gather the data, beat it up a bit and send it to the LED displays instead of to an Android via blue tooth. It works and I can read it from across the room but it doesn’t do any of the magic that happens inside a tablet.

Stragenmitsuko if you’re interested there’s not much to it, PM me and I’ll get the wiring diagram and code to you or I can just put them into the download section.


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## bmac2 (Jun 17, 2018)

On with the build. 
The front and rear bearings are basically the same just the rear being shorter so I sandwiched them together with a couple drops of super glue before milling and drilling both to match the drawing for the front bearing. The rear bearing will have 2 extra holes near the bottom but I’ll live with that for the sake of alignment.


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## bmac2 (Jun 17, 2018)

When rounding over the top of a part I always worry about going over with one of the passes and digging a chunk out of the part. This time I decided to use my Arduino controller. Once I had it set up and had the angle worked out all I had to do was press “A” forward. “B” reverse’ and move the Z axis down. It worked pretty slick but the waste peace on the last pass sure did some chattering.


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## bmac2 (Jun 17, 2018)

Separated the 2 pieces with a little heat and a good smack then did the same thing with the rear bearing to bring it to size.






Drilled and tapped the mounting holes in the bottom of the bearings and the matching holes in the base. The DRO must be working because the fit is great and actually line up!






Drilled and reamed them to .375” and got the bushings installed and everything still lines up. That doesn’t always happen when I disassemble and reassemble things.






  It’s starting to look like something. Got the crank done, it’s a pretty straight forward milling and drilling.






The parts count is climbing so I happy. Next up I think I’m going to tackle the flywheel.






Personally I don’t like a flywheel that just looks like a 5Lb. lump so I’ll be going with the MF11 per the drawings. But for now I can hear my BBQ calling me.


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## stragenmitsuko (Jun 18, 2018)

might I suggest a curved spoke ( filip duclos ) flywheel .


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## nel2lar (Jun 18, 2018)

Bob
Very nice work.
Nelson


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## bmac2 (Jun 19, 2018)

Thank you Nelson

Stragenmitsuko I thought about that and I think they look great on my Webster. Yep, this thing started out as “I wanna build a Webster”. I deviated from the plans _just_ a little bit. 

https://www.homemodelenginemachinist.com/threads/water-cooled-webster.23224/







I didn’t get much done today what with work, eating dinner and having a nap but I did get the flywheel roughed out. Environment Canada has issued a heat warning for the rest of the week so with the shop being in the basement (a nice 19c down there) I hope to get it finished during the week and start on the gear over the weekend.


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## bmac2 (Jun 22, 2018)

When doing a spoked flywheel I like to map everything out in CAD labeling all the drill points and use the center as zero. From there I create a drill chart showing me the X and Y offsets for each hole.





This is my cheater for setting up the 4” rotary table. It has a .375 shank that fits the holder with a plug that’s a snug fit into the center of the table and a handy .25 reamed hole. It may not be as exact as indexing but it’s very close and real fast to setup.










Then by putting a short piece of drill rod into the hole in the plug and I can use it to align the flywheel blank on the table. Clamping on a small table can be challenging, the setup looks dodgy but it feels very solid. One of the things I like about this setup is that everything is at my “0” mark.










Used a 1/8” end mill to drill out all the end points then milled out to top of the openings. My wife reminded me that I had to go to work in the morning so I returned everything to “Zero”, locked down “X” and “Y” and called it a night.


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## bmac2 (Jun 22, 2018)

Today it’s 30c outside, but it’s nice and cool in the shop. Without the check list and a DRO there is no way I’d attempt stopping in the middle of this. But thanks to my handy highlighter pen it only took me a minute or two to get back to making chips. Finishing the spokes didn’t take long, just had to set the angle and offset and mill them out.










It came out just like the drawing and it looks good . . . . But Stragenmitsuko had brought up curved spokes and that got me thinking. With a flywheel it’s the mass along the outer diameter that counts. With a spoked flywheel I don’t think the spokes add much so I decided to add a little style by running the mill down the middle of each spoke. I like the look but I’m thinking I might have to add some weight around the rim.






I got the notch cut out in the base and I’m calling it a night.


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## stragenmitsuko (Jun 22, 2018)

that is an absolutely beautifull flywheel !


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## bmac2 (Jun 22, 2018)

Thanks Stragenmitsuko. 
Hay You started it. I’m so close to where I have to think about the gears I would have probably stopped with the stock one.


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## Brian Rupnow (Jun 22, 2018)

Very nice work and great documentation.--Brian Rupnow


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## bmac2 (Jun 25, 2018)

Thank you Brian I’ve been following your Double Oscillator build. 
Somehow I _knew_ you were going to work a pulley onto it.


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## bmac2 (Jun 25, 2018)

I didn’t get much done on the weekend, our anniversary was Sunday, but did manage to sneak in a few hours on Saturday.

Knocking out the eccentric was just some simple off set turning in the 4 jaw with a little drilling and reaming.






And I guess this is where the drawings turn into more of a guide line. I’m fairly confident in my math so I guess the only way to see if this is going work is to just do it.






The gear arm is as in the original drawing with the offset for the orbiting gear was reduced to .312. The hole for the piston rod screw is drilled for a no.6 because as it turns out I don’t have a no.5 die.











I need is a 21 tooth gear with a .6155 diameter. That didn’t work out with the gear cutters I have but after trying one in aluminum it fit the ring gear ok(?) so I went ahead and cut one from brass.












In the instructions it says “Piston rod screw must be exactly centered between two teeth”. I may look out a bit in the pictures but it’s about as close as I can imagine getting it. The plans call for silver solder here but for now Loctite will have to suffice.


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## stragenmitsuko (Jun 27, 2018)

been wondering as I followed this build .
You've already made the piston and cilinder , right .
If a smaller ring gear is used , that ought to affect the stroke of the piston .
Did you adapt the dimensions of  the cilinder/ piston also ?

Pat


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## bmac2 (Jun 27, 2018)

Hi Pat. Yes the gear arm is .063 shorter than Elmer’s plans so the cylinder and connecting rod need to be 1/8” shorter . . . . . . . unfortunately I forgot about that when I started, and made them straight off the plans. This will leave an extra .063” (1.5mm) between the piston and the heads at dead center but I don’t think it will affect performance. If worst comes to worst I’ll just make a thicker piston to fill the void.


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## stragenmitsuko (Jun 28, 2018)

Bob , 

I think I understand now . 
The stroke is twice the pitch diam of the internal gear . 
Crank throw and gear arm have to be of equal length , that makes it 4 times .375 from tdc to bdt 
on the original plans wich results to 1.5 inch stroke .  
At tdc the crank centre is on one end of the internal gear , and the con rod on the other end . 
Dividing it exatly by 2 for any angle , wich results in the straight motion . 
Hence the importance of  the centrelines passing trough the teeth centres . 

Does that sound about right ? 

Been also looking at my box of internal gears , but all I have are ring gears with odd numbers of teeth . 
45 , 47 and 53 teeth . Those won't work for sure .


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## bmac2 (Jun 29, 2018)

This thing is hard to explain isn’t it?

Hang in there for gears. There have to be thousands of dead drills out there.

Every time I saw someone build on one of these things I’d start messing around in CAD.

This is what I’m going on. I don’t feel that the size of the ring gear is all that critical. As long as it has an even number of teeth and the orbiting gear is half the size it should work. Then so long as the holes in the gear arm set at half the diameter of the orbiting gear this will put the piston rod screw running along a line with the center of the crank shaft. In this drawing the diameter of the gear could be 2 inches of 2 feet and the geometry stays the same. It would have to fit within the envelope of the engine of course.






Sorry, I’m not sure if that even makes sense to me and I wrote it!

My plan is to make an adaptor ring with an outside diameter the same as the gear called for in the plans and bore a hole into it to fit the gear I’m using. This way most parts are per the drawings. 
 You’ll notice that the orbiting gear runs in the opposite direction of the crank shaft.


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## stragenmitsuko (Jul 2, 2018)

Nice cad work , and it makes perfect sense . 

Tell me , what cutter did you use to make the gear ? 
21 tooth gear with a .6155 diameter , I 'de say it's a 0.7 Mod gear .


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## bmac2 (Jul 3, 2018)

Oh the gear . . . . The math just didn’t work out with the cutters I have. On top of that I couldn’t come up with a way of measuring the ring gear teeth. What I ended up doing was making a couple of gears from aluminum and just trying them. In the end I used a Module 1 PA20 No.3 and a small V file to tweak the teeth a bit. It is going to be noisy but it should work.


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## bmac2 (Jul 3, 2018)

I got the crank and piston rod screws done, these are straight forward turning made from the drawings.  Then slotted them with a Dermal cut off wheel


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## bmac2 (Jul 3, 2018)

I’m using a ring around the ring gear for 2 reasons, one it gives me a way to mount the gear and 2 it simplifies things immensely by keeping as many of the dimensions as possible the same as in Elmer’s original drawings. As things normally go I need something 2 in. in diameter and all I have at hand is the 3 ½ in. I used for the flywheel.











After a bit of scratching lines and procrastinating I faced off the blank, and reamed a .25 hole in the center. Then using a piece of drill rod I aligned the bearing mount on the blank and used a transfer punch to mark the positions of the mounting holes.











Back on the lathe I took the outside down and started boring it out.


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## bmac2 (Jul 3, 2018)

That done it was time for some major cleanup. I was ready to hall it out to the bin when my wife spotted it. She thinks she’s found where the “tree rat” (pronounced Squirrel) has been getting under the garden shed and was off to fill in the hole with aluminum shavings.


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## bmac2 (Jul 3, 2018)

The gear looks to be MIM (https://en.wikipedia.org/wiki/Metal_injection_molding) and feels very hard with 4 tabs that are not evenly spaced. After some layout I broached 4 shallow notches and parted off the ring. This turned out pretty good and the gear is a firm press fit into the ring.


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## bmac2 (Jul 8, 2018)

Ok back in the saddle. I made up the spacers that go between the front bearing mount and the ring. These are just ¼” aluminum rod drilled to fit 2-56 screws and parted off. The only thing I had to change was the length as the gear I’m using is thicker than the one called for in the plans. I got everything mounted up and I guess this is where the fun begins. I had my doubts that this would work “out of the box” and it didn’t. It looks like “_Piston rod screw must be exactly centered between two teeth_” works when you use the prescribed gear but this is going to take some fiddling.



On the up side the hole for the piston rod screw looks to line up with the little tit on the shaft left by parting it off so that’s on the plus side. I am very glad that I used Loctite instead of silver soldering here. A little heat and the two pieces separated cleanly.






The parts count is going up and looking in the box somewhere along the line I made the eccentric strap.


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## stragenmitsuko (Jul 8, 2018)

Looks like the movement is straight allright , just not parallel to the base . 
I guess a little tweaking of the ring and or the orbiting gear ought to take care of  that . 

But look on the bright side , the gears do mesh and don't bind .


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## bmac2 (Jul 10, 2018)

Hi Pat, I think if the gear was any _freer_ it would drop right into the sloppy category but that might work in my favor. I’ve been messing around with it on and off for the last couple of days and started by rotating the orbiting gear counter clockwise one tooth and from there just playing around with the positioning of the gear arm. I think I’m getting close but finding the sweet spot is touchy. The tolerances between the gears, gear arm position and the height of the cylinder mount on this thing are tight.


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## Iampappabear (Jul 11, 2018)

I have been "tinkering" with a geared engine between working on my serious projects and came upon the same issue of ring gear.  Part of the intent was to use as many parts as possible that were lying around in my shop so my solution is to use a timing belt glued inside a ring.  The inner gear is just a stock timing sprocket.  Looks promising but having problems finding the best adhesive for rubber to aluminum.


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## a41capt (Jul 11, 2018)

Not sure about the type of rubber, but I’ve always had good luck with 3M premium weatherstrip adhesive for rubber to all metal bonds.  The stuff is ugly looking, and we always called it “monkey snot”, unless they’ve cleaned it up recently.

If the belt is silicone based, there’s damn few things that will bond well with it though...


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## bmac2 (Jul 12, 2018)

Hey pappabear. I’m with you. I try not to lay out too much hard cash on my hobbies unless it’s tooling. I can’t see any reason a timing belt wouldn’t work so long as it’s a 2 to 1 ratio and you can keep it on the center line. I’ve had good results with Permatex Plastic weld attaching nylon standoffs to aluminum for electronics project but it STINKS! Where it says “Well Ventilates Area” it means middle of the back yard with a wind.

a41Catpt In my experience with rubber adhesive the more it looks like “_Snot_” the better it works.

For me it’s going to drive me nuts. It feels _Sooo close_ but I just haven’t found that sweet spot. It’s not bad but I still have some binding between 3 and 6 o’clock.


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## bmac2 (Jul 14, 2018)

I am going to rename this thread “Elmer’s #5 Geared Engine . . . *YES*” and dropping the maybe. The gear arm was a snug fit on the gear, so I could rotate it. By just tweaking it a bit each time and trying it I couldn’t hit the spot. Then I put a couple of dial indicators on the shaft and cylinder block and notices that the cylinder was lifting at the end of the stroke. Then I started using feeler gauges as shims under the cylinder, and by trial and error found the sweet spot. I but a drop on crazy glue on the gear arm to hold it in place, drilled it and used 3 bins to mount it to the gear. To my relief when I got things back together it still runs free with no appreciable binding.


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## Rockytime (Jul 15, 2018)

Very interesting. I started the geared engine perhaps at least 25 years ago. Life sometimes gets in the way like other pursuits.  At just a couple of months away from 80 there are several things I no longer do. However, this is kind of a reminder that I should perhaps pick it up this winter. Sitting in a basement in the summer won't cut it. You have done very well. Elmer's engines are always interesting.


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## bmac2 (Jul 15, 2018)

Wow Les it looks like you have all the big pieces done and what you have looks great. If you haven’t made the valve rod yet I can strongly recommend building it up rather than making it out of one piece. Winter is coming sooner than I think any of us want and around here we can start seeing snow in October. Ok except for Australia and the rest of the southern hemisphere then I guess winters almost over yay.


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## bmac2 (Jul 15, 2018)

Now that I have it dialed in I know how tall the cylinder “foot” has to be and after the match (congratulations to France and Croatia) I got it milled to size and drilled for the mounting screws.













This is the part I was tempted not to post.

But . . . .

With the foot made I got the engine assembled and roughly timed. I couldn’t feel any binding so I hooked up the air and the piston slammed to the end of the stroke and stopped. I played around with the eccentric for a while but it wasn’t going anywhere.

It was time for a tear down to see what was going wrong and this is where things get a bit _embarrassing_.

Now earlier in this thread I had to fix my DRO, so I have digital read outs on my mill. I have shown a couple of CAD drawings and I have used a CAD or 3D CAD system for over 25 years. So how did I manage to mess up the 9 holes in the valve plate this badly?






I’ll make a new one tomorrow but maybe l should use a ruler, punch and a hand drill.


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## bmac2 (Jul 17, 2018)

I got the NEW valve plate made and spent a couple of hours listening to an audio book while lapping both sides on the surface plate (Chinese Thom stone). Then once again got the engine assembled and roughly timed.






Oh Mr. Verburg what had you eaten the night you dreamed this up?

The timing is way off and it’s drenched in oil, running rough but the little SOB does run. I can’t for the life of me think why I left that shaft so long but now I just have to get the timing set, clean it up and do some fit and finish.


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## minh-thanh (Jul 18, 2018)

Wow... that's nice !


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## stragenmitsuko (Jul 18, 2018)

congratulations , beautifull job .


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## Cogsy (Jul 18, 2018)

That is a cool engine. Congrats.


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## justintime (Jul 19, 2018)

kwoodhands said:


> Your end mill has a 1/4" shank which is not common for the holders. Make a holder from scrap round 1018 or what ever you have . Bore the hole slightly less than .250. Then ream the hole to .251. Turn the outside of the blank to fit an endmill holder you do have, I used 3/4" because I rarely use that holder. Turn the work to .749.  Mill a flat for the set screw on the holder, drill and tap for a setscrew for the 1/4" endmill. Much better than using a drill chuck.
> The holder will have less runout than most drill chucks. You need as close to no runout as possible with tiny endmills.
> 
> mike


Hello,  not sure if I grasp exactly what you are suggesting, but I would advocate for buying holders for such tiny end mills.  I was fortunate enough to have them supplied for every size imaginable where I was employed during my machine career so I have a drawer full of all sizes        from ( 1/16" to 3/8"  ID ) all with 3/8" shanks.  They are not pricy to buy, have hardened and ground shanks and they run dead-on.  Just something to consider before investing too much time in making one ( or more ) which will not run as perfectly as a purchased item.  Luck !


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## bmac2 (Jul 21, 2018)

Well I’m calling it done. To everyone that dropped by during this weird adventure, Sergulbka, Anatol, TonyM, Rudy, marioserafica, a41capt, kwoodhands, stragenmitsuko, aka9950202, nel2lar, Brian Rupnow, Iampappabear, Rockytime, kvom, Cogsy, minh-thanh. I’d like to say thanks for the encouragement and motivation to keep up the posts.

There that done and before this thread turns into a “Chick Flick” some last pics of the engine. 
The first thing I did was cut that shaft to length! Then to finish it off I wrapped the cylinder with some walnut veneer for lagging held in place with some 1/8” wide brass bands. It turns out that I was correct when I said that the flywheel might be a little light. At its slowest speed the flywheel is almost coming to a stop at each end of the stroke but I like the look and I don’t think I’ll change it. In the second last picture you can see one of the pins I put into the gear arm to keep it in position. I’ll post a final video of it in “Finished Projects”


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## kvom (Jul 22, 2018)

You did a great job with this.  My only suggestion would be to replace the slotted screws with model scale hex screws,


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## bmac2 (Jul 23, 2018)

kvom I would have to agree with you. I am not a fan of slotted screws at the best of time. When I came across the ring gear I also found a box of those 2x56 SS screws. If this was a model of an actual engine I would have at least swapped them out for cap heads but it’s more of a novelty and with the two big slots in the drive end I decided to just leave them as is. But in the end I’m just happy that it runs and it is fun to watch


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## natalefr (Jul 24, 2018)

Super engine


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## Nigel C (Jul 24, 2018)

That is a beautiful engine.  Many thanks for sharing both the journey and result.


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## kwoodhands (Jul 25, 2018)

justintime said:


> Hello,  not sure if I grasp exactly what you are suggesting, but I would advocate for buying holders for such tiny end mills.  I was fortunate enough to have them supplied for every size imaginable where I was employed during my machine career so I have a drawer full of all sizes        from ( 1/16" to 3/8"  ID ) all with 3/8" shanks.  They are not pricy to buy, have hardened and ground shanks and they run dead-on.  Just something to consider before investing too much time in making one ( or more ) which will not run as perfectly as a purchased item.  Luck !


 
I bought a set of R-8 holders that included 3/16,3/8,1/2,5/8,and 3/4" diameters. I often use small endmills with shanks that are either 3/16" or 1/4" for 1/64 / 7/64 endmills.
There are few sources for 1/4" diameter holders but after  reading your reply I did find reasonably priced 1/4" and other sizes on E-bay.
$18.75 for the 1/4" , fair price . Thanks for your reply, I didn't know the holders came in so many sizes, I went buy the sets you usually see advertised.

mike


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## a41capt (Aug 9, 2018)

Congratulations on one fine looking and running engine!  I enjoyed watching your build and your various work around during construction.

Thanks for sharing it all with us!

John
Camp Verde, AZ


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## Cymro77 (Aug 10, 2018)

Fascinating read.  Cool engine.


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## Brian Rupnow (Aug 10, 2018)

Congratulations!! You have done yourself proud. Overcame adversity, worked until you have a good looking running engine.---Brian


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## bmac2 (Aug 13, 2018)

Thanks guys. I have been tempted to add some weight to the flywheel by drilling 6 ¼” holes in alignment with the ends of the spokes and filling them with either lead or steel pins. But I’m quite happy with the engine as it is and there’s always that next project calling.

Who knows maybe this will motivate someone to try that next engine or other project even if they don’t have all the "_correct_" parts or materials.


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## JohnBDownunder (Nov 8, 2018)

Thank you for posting a most enjoyable read and model. 
       For what it's worth I have in the past increased the mass of an aluminium flywheel by drilling holes in the outer rim and filling them with lead. Lead being about 7 times denser than aluminium it works. 
   Call the filled holes decoration or paint the rim??
Great model.
John B


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## propclock (Nov 8, 2018)

Great engine , great read, did you ever post the dro code?
I cut an internal ring gear using Gearotic I used delrin for low noise. 2X ? Elmer size, 
I like engines bigger and 1/16th was my smallest
end mill needed for milling the teeth, You are motivating me to
finish it. At the time the cost of boston gears and Gearotic
License was the same. I use Gearotic quite a bit. 
Thanks for a great project.


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## bmac2 (Nov 16, 2018)

propclock said:


> Great engine , great read, did you ever post the dro code?



Propclock I must apologise for not getting this out to you sooner. I planning to put it into the download section but was having trouble getting it to upload and then just plane forgot. I’ve put the wiring diagram and the Arduino sketch for the DRO display and the Tachometer in the zip file.

For prototyping I used a UNO because it has the 3.3v supply needed for the scales. For the final build I used some 5v Mini Pro’s I had around so I had to add a separate 3.3v regulator and use a voltage divider on the data lead going out to the scales.



The LED displays are great and unlike the original iGaging I can read them from across the room. I got them from Banggood for around $4 Canadian https://www.banggood.com/MAX7219-Re...U-p-907849.html?rmmds=search&cur_warehouse=CN

The tachometer has both the I2C and parallel wiring diagrams.


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## oliver jenner (Jan 15, 2019)

Hi b mac, great work. Been really interesting following your progress. Im also interested in what you have done with the DRO and was just wondering if you had the arduino sketch to make a metric readout? Thanks, Oliver


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## bmac2 (Jan 17, 2019)

Hi Oliver welcome to the forums. 
I got the sketch from WMello on another forum and it just worked straight out of the box so I’ve never really looked at it. I think if you change Line 112 to read v=(DroMea*25.4); it should work.


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## oliver jenner (Jan 17, 2019)

Thank you, been following builds on here for a while but have only just decided to register. There are a lot of talented people on here and great projects. 

Ok will try changing that line of code and see what happens. Cant see why it wouldn't work. I dont suppose you would consider shearing the PCB design you had made for the arduino boards to go on?

Thanks, Oliver


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## bmac2 (Jan 20, 2019)

No worries Oliver

I have to say that my filing system sucks, what I could find was scattered all over my laptop and two network drives. But in my defence I probably didn’t think I’d need them again. The wiring list and wiring diagram will probably be the most useful. I used toner transfer to make the board but managed to find the positive and negative for the CPU board. The breakout board for the scales uses surface mount USB “A” connectors so if you cable them out is would be a lot easier. I’m not sure if the power/tach board is the one I ended up using. It has the power jack, 5v and 3.3v regulators and an input jack for the tach. The file _CPU_Mounting_Board_etch_silk_top_ shows where the three jumpers go on the board. Hope you can make sense of this and if you make one how about posting a build.


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## oliver jenner (Feb 4, 2019)

Thanks again for uploading the files. They are going to be a great help. I’m sure I will be able to make sense of them. Will definitely try and post a build when i have collected all the components together.


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## lancer (Jan 30, 2021)

Hi Bmac2
I am interested in this project which I have been ages to find something similar to it.
I has to questions if you no not mind.
1. Can you please tell me the value for the resistors you used with W2 to ground in your wiring diagram.
2. I have a china vernier, will this project work with it. ie batter voltage is 1.5V and not 3.3V as you used.
Thanks for uploading the project.
Lancer


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## Brian Rupnow (Jan 30, 2021)

Bmac--Somehow I missed this thread. Your engine looks and runs very well. Old Elmer designed a lot of really neat stuff, but I find that in general, they are just too damn small to be comfortable machining. I have redrawn a couple of his engines at 1.5:1 scale, and I find them much easier to manage.


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## bmac2 (Jan 31, 2021)

lancer said:


> Hi Bmac2
> I am interested in this project which I have been ages to find something similar to it.
> I has to questions if you no not mind.
> 1. Can you please tell me the value for the resistors you used with W2 to ground in your wiring diagram.
> ...



Hi Lancer

If you want to interface to a china Vernier have a look at this link.

Arduino reads digital caliper - martin's useless and useful creations

I was messing around with it a while ago and the code works. The code as written just outputs to the serial monitor in the Arduino IDE (your computer) but it would be simple to have it go to any type of display you want.


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## lancer (Feb 1, 2021)

bmac2 said:


> Hi Lancer
> 
> If you want to interface to a china Vernier have a look at this link.
> 
> ...


Hi Bmac2
Thanks for the reply, I will try to understand the way to build it.
One more thing can you tell me the value of the two resisters you use in you project, what I can see from the video they look to be 100 Omhs.
Lancer


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## bmac2 (Feb 4, 2021)

Sorry Lancer I missed that. I assume you’re talking about the 2 resistors on each of the USB connectors going out to the scales. That’s just a voltage divider to drop the 5v clock signal from the Arduino to the 3.3v that’s safe for the iGaging scales. R1 (going to +5) would be 100ohm and R2 (going to GND) would be 200ohm to give an output signal of 3.333v.

https://ohmslawcalculator.com/voltage-divider-calculator

For a 1.5v vernier caliper R1 would be around 250ohm and R2 100ohm. That would drop it close to 1.5v (1.429v). Being butt lazy I have an app on the old i-pod I use to listen to audio books/music in the shop.


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