# Moteur Oscillant - Double acting Oscillator Twin



## cfellows (Jul 29, 2011)

I've tabled the Rudy Kouhoupt twin marine engine for the moment and started on the French designed Moteur Oscillant. Stew Hart and Bogs have both built excellent versions of this engine and I think it might be suitable for a boat or land vehicle later down the road.

Here is a link to the original plans:

http://jpduval.free.fr/Moteurs_vapeur_simples/MV%20deo%2010x20.pdf

I have increased the size by about 10% and converted all the measurements to inches. My engine will have a 7/16" bore and 7/8" inch stroke. I opted to use aluminum since I had a large piece the right size and I wanted the engine to be as light as possible, especially if it winds up in a boat.

I've got the frame and cylinders, pretty well finished. I've also finished both cylinder end caps except for the mounting holes. Here's a few pictures of the work so far. If you look closely at the first picture, you can see a small o-ring nestled in the middle end cap piece.

















Chuck


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## m_kilde (Jul 29, 2011)

Hi Chuck

This engine is a great design.

I'm not sure however if it will be a good idea to use aluminium for both the cylinders and the engine housing, I'm affraid the two parts will fuse together


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## Blogwitch (Jul 30, 2011)

Chuck,

I am not trying to teach you to suck eggs, but I too am a little worried over your use of ali.

I have made a fair amount of these engines in the past, and also passed over the modded versions of the engine to Stew so he could make a batch of them for sale.

My main worry is when it comes to run on steam. It will be good on air, but the heat produced when steaming changes the whole characteristics of how the engine operates.

The plans do have a bit of a flaw in them. If you make the control disk on the top as per the plans, the operating lever sits over one of the cylinder tops, you need to move the lever groove so that it sits to the side of the main frame when in operation.

My two versions of the same engine showing the modified spring arrangement which makes it a lot simpler build







John


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## SBWHART (Jul 30, 2011)

> The plans do have a bit of a flaw in them. If you make the control disk on the top as per the plans, the operating lever sits over one of the cylinder tops, you need to move the lever groove so that it sits to the side of the main frame when in operation.



You just have to move the slots round 45 deg, on Johns recomendation I also added a groove for a stop pin.

Like this











I'm not to sure about the use of ally also.

Why are you concerned with the weight from my limited understanding weight is added to a boat to give it trim.

They do build up into a very nice engine though.

One other area you may concider changing is the crank webs pinched onto the shafts, after building I though that it may have been better to use small 2mm grub screws to fix the webs, may well be worth doing a little experiment with this.

Hope this helps

Stew


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## Tony Bird (Jul 30, 2011)

Hi Chuck,

Looking good. I don't know whether aluminium is good for making the cylinders and port block as far as wear and lubrication go, I have never tried it. I have used aluminium to make pistons in brass or bronze cylinders where it works very well. So I suppose a brass piston in aluminium cylinders would work the same? I wouldn't worry about the engines weight, in all the boats I have fitted steam engines to have had to have ballast added to them. 

Regards Tony.


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## compspecial (Jul 30, 2011)

Hi Chuck, workmanship up to your usual high standard I see! are those ball bearings I see in the main bearings? and is the central frame laminated from three pieces?
 As to materials, I was always told that sliding friction between similar metals is never a good idea (except cast iron ofcourse) but aluminium seems to get on pretty well with steel and most non ferrous metals, like in alloy master cylinders with steel pistons and ofcourse aluminium valve bodies with steel pistons in auto transmissions. Your sheer output of projects always amazes me Chuck.
            regards Stew


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## mklotz (Jul 30, 2011)

I built Elmer's reversing wobbler...






using aluminum for the cylinder and standard. The first time I ran it (on air) it seized up to the point where I couldn't rotate the cylinder using my hand. After separating the two parts and redoing the surfaces, I lubricated the interface with Neverseize and now it runs fine on air (I've never run it on steam).


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## cfellows (Jul 30, 2011)

Thanks, everyone, for the comments & compliments. 

Bogs, yours was the first example of this engine I saw and liked both your versions immediately. I had decided I wanted one someday. 

m_kilde, what are your frames and cylinders made of? They don't look like brass? Nice looking engine. :bow:

Stew (sbwhart), I saw the video of your engine running and liked the way it ran and sounded. 

Stew (compspecial), those are flanged ball bearings in the frame. I'm a little concerned that they may not be stainless and might pose a problem at some point. The frame is carved out of one piece. As to the volume of my work, well, I'm retired, so I have a lot more time. I also work pretty fast which results in lots of mistakes and re-do's. I'm trying to slow down and be more careful! Finally, it seems I finish about 1 out of every 3 projects I start... :-[

Tony, thanks for the comments. Perhaps my concern for weight was really false justification to preserve my stash of brass... 

Marv, thanks for sharing your experience. I can see how an aluminum piston and cylinder might seize but I sure wouldn't have thought that two flat aluminum surfaces rubbing together would be a problem. You've kind of convinced me that aluminum might be a issue. Nicely built version of Elmer's engine, by the way. Very pleasing to look at. 

I think the real reason I started with aluminum is that I tend to be kind of frugal with my brass. I usually make mistakes and have to remake pieces and don't like wasting my brass. Turns out I did have to make a second copy of the frame because I miscalculated the length of the original by 1/8"! I didn't want to use steel or cast iron because I don't want to deal with rust.

I do like the look of brass, particularly in combination with some bright steel and polished aluminum. I'm thinking once I get all the wrinkles ironed out in the prototype, I may remake the cylinders and frame out of brass.

Chuck


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## mklotz (Jul 30, 2011)

cfellows  said:
			
		

> I usually make mistakes and have to remake pieces and don't like wasting my brass. Turns out I did have to make a second copy of the frame because I miscalculated the length of the original by 1/8"! I didn't want to use steel or cast iron because I don't want to deal with rust.



One of the things our hobby will (eventually) teach you is to "proofread" your setups before pushing the "post" button.

I'm reasonably good at mental arithmetic but I still make it a point to do most shop calculations on a calculator. When I have to derive a dimension from others I'll do it in (at least) two distinct ways. If the results don't match, I know I've screwed up.

Working with fractional dimensions is even more infuriating. Fortunately, modern scientific calculators have the "a-b/c" key for dealing with that.


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## cfellows (Jul 30, 2011)

mklotz  said:
			
		

> One of the things our hobby will (eventually) teach you is to "proofread" your setups before pushing the "post" button.
> 
> I'm reasonably good at mental arithmetic but I still make it a point to do most shop calculations on a calculator. When I have to derive a dimension from others I'll do it in (at least) two distinct ways. If the results don't match, I know I've screwed up.
> 
> Working with fractional dimensions is even more infuriating. Fortunately, modern scientific calculators have the "a-b/c" key for dealing with that.



I don't know, Marv. I've been at this a long time, and I still get impatient to start cutting metal. And, I usually pay the price by cutting more metal than the project actually calls for. I have to say, however, that recently I have started taking more time to get things right the first time. There is a huge satisfaction in completing a part that is right on the money.  8)

Chuck


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## cfellows (Jul 30, 2011)

I've redrawn the metric version of this engine to the same scale as the original. It appears that the cylinder ports are completely covered from about -3 deg to +3 deg before and after center. I'm a little surprised about this. Did you folks who have built this engine build the ports exactly to specification?

Thx... Chuck


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## SBWHART (Jul 30, 2011)

Chuck

I didn't have the correct metric drills so i used the nearest number drills for the ports, can't remember what they were, but it didn't seem to make any difference and I know one of the engines is running well on steam.

Also the cranks are quartered so at least one of the cylinder is powering wherever it is in the cycle, I'm not an expert on this but I would think it would make the valve timimg less critical, but I would open that up to debate.

Stew


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## Blogwitch (Jul 30, 2011)

Chuck,

I made mine exactly to the drawing port wise, and it works perfectly, so don't have any worries on that score.

What a lot of people don't realise that this engine is a slow revving long stroke type (double the bore size) and produces exceptional levels of power for it's size.

One of mine easily replaced a large Cheddar Gemini engine in a 50" open launch and had enough power to push it along at well over scale on only 25psi. At 5psi it is almost impossible to stop the shaft on the horizontal version, you need vice grips to stop it. Look how tiny the engine actually looks in the 50" boat.







And this is also one of mine fitted into John Somers 42" Krick Victoria. Again, more than enough power even for a very beamy boat such as this.









IMHO, the vertical one will easily turn a 3" (or even larger) 45 degree steam prop without batting an eyelid. They only turn over at about 150 to 200 RPM top speed when running in a model boat


John


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## SBWHART (Jul 31, 2011)

Just checked

for the 1.7 mm port I used a No 51 drill = 1.702 mm

for the 2.2 mm port I used a No 44 drill = 2.184 mm

If you've increased the bore and stroke I guess it wouldn't be a bad idea to increase the ports/steam ways in proportion.

Stew


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## Tony Bird (Jul 31, 2011)

Hi,

When making oscillating cylinder engines I have always followed Deryk Goodalls advice and made the two holes in the port face and hole in the cylinder the same size with no or very little lap. Using this system calculating the size of the holes is half the centre distance of the ports in the port block. In this engine it is 4.90mm so I would use ports of 2.4mm giving very a small amount of lap. The theory being that it is the maximum size possible for the flow of steam and its exhaust. The cylinders move so fast that their is little chance of the steam going straight to exhaust. Certainly in the Mamod steam locomotives which had quit a large lap their performance was greatly improved my making their steam and exhaust ports larger. I think it might have been Tubal Cain who said on his high speed oscillating engine the ports were large enough that they overlapped each other. I have never tried this. The steam pipes ID should be the same or larger than the diameter of the ports. I do use a larger exhaust pipe than steam pipe but only after any reversing system used as until then all ports and pipes are used for both steam and exhaust. Hope this makes sense.

Regards Tony.


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## doubletop (Jul 31, 2011)

Me too............

Engine






With the marine boiler 






Both builds were posted on HMEM

I made it to the drawings and it worked straight out of the box so didn't bother with checking the ports or messing with it. Great little engine.


Pete


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## cfellows (Jul 31, 2011)

Thanks for the measurements, Stew. I had made the holes in the port block 3/32" and the holes in the cylinder block 5/64". This proportionately larger than the original plans.

Tony, since I'm going to remake the cylinders (and perhaps the frame) out of brass, I think I will go with larger port holes in the cylinder. Most of the fun with these projects is making changes to see what the results are, although I suppose determining the results is difficult if you don't make the original to compare it with... :-\ Wish I could stop arguing with myself!

Pete thanks for the pics and the reference. I looked up your build thread and saved a link to it for reference. I also found your videos and had a look. Nice running engine.

Chuck


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## cfellows (Aug 1, 2011)

sbwhart  said:
			
		

> One other area you may concider changing is the crank webs pinched onto the shafts, after building I though that it may have been better to use small 2mm grub screws to fix the webs, may well be worth doing a little experiment with this.
> 
> Hope this helps
> 
> Stew



Stew, what didn't you like about the crank web pinched onto the shafts?

thx...
Chuck


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## cfellows (Aug 1, 2011)

Pete, did you solder the connecting rod journals to the crankshaft webs? 

Pete, Stew, Bogs, it's not clear how he piston rod attaches to the piston. I would have assumed threads but I can't find any indication of thread size in the original drawings?


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## ironman (Aug 1, 2011)

Chuck, glad you are building that engine. Do you have in mind what type of boat you would like to put it in?

Following along with you on this. I know you will build a super nice engine.

ironman (Ray)


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## cfellows (Aug 1, 2011)

Thanks, Ray. It always feels like a gamble whether it will work out or not. 

I've remade the engine frame out of brass. Changed some of the dimensions a bit, following Tony's suggestion. I made the cylinder ports and frame ports the same size using the bigger diameter of the two. I've drilled all the holes except the main inlet and exhaust ports. I also am holding off on drilling the crankshaft bearing holes, awaiting the arrival of some beefier flanged ball bearing races. In the interim, I'm also working on the drawings and designing the remaining parts.

















Chuck


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## SBWHART (Aug 2, 2011)

cfellows  said:
			
		

> Stew, what didn't you like about the crank web pinched onto the shafts?
> 
> thx...
> Chuck



It had a tendency to slip, you really have to get the screws good and tight, and pinch in the webs a bit before you assemble the rods, when you get it gripping it works fine:- but I don't think it looks to good, I think grub screws would be far neater, but thats just me.



> Pete, Stew, Bogs, it's not clear how he piston rod attaches to the piston. I would have assumed threads but I can't find any indication of thread size in the original drawings?



Yes thats correct they are screwed on same size as the rod M3 I think, I added a bit of thread lock.

Hope this helps

The engine is comming on great I'm sure it will be a good runner.

Stew


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## mzetati (Aug 2, 2011)

cfellows  said:
			
		

> I've remade the engine frame out of brass.



Hi Chuck,

glad You did it! 
On my very first engine, the David II wobbler, I had made the column and cylinder in aluminium: as soon as I had a nice finish on both surfaces, I set the pivot and moved them a few times by hand.
Three or four strokes, and they got hard to move.
Learnt the meaning of the word 'galling' the hard way.
I've built one of those MV-DEO some years ago: definitely a nice runner, though I put bronze bearings in place of the ball racers.

Marcello


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## cfellows (Aug 2, 2011)

Got a little more done today. Finished up the crank disks and completed the flywheel. I also located 4 ball bearing races identical to the ones I had just ordered on Ebay. Not sure how I missed them, but now I will have some extras when they arrive in the mail.

Here's some pictures of the assembled engine so far. Still have to do the pistons and rods as well as the manifolds and the reversing valve. Oh yeah, then I get to start on the base...


























The bore and stroke on this engine are 7/16" & 7/8" respectively. This makes the overall displacement about 37% greater than the original engine with a bore & stroke of 10mm & 20mm respectively. Guess that means it'll take 37% more steam to run it... hadn't thought of that.  ???

Chuck


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## lazylathe (Aug 2, 2011)

Looking great Chuck!!! Thm:

Can't wait to see what type of base you make for this engine!!!

Andrew


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## doubletop (Aug 3, 2011)

As usual that's looking good Chuck, you'll need a 37% bigger boat 

_(now somebody can put me right that the relationship between engine bore, stroke, boat displacement/length/drag whatever isn't linear)_

Great job

Pete


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## steamer (Aug 3, 2011)

Doubletop,

That is a large can of worms...and I don't want to do that in chucks thread....it "depends". ;D

Dave


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## cfellows (Aug 4, 2011)

I had forgotten how finicky these little oscillators are to everything being in alignment. I got the pistons and rods finished, put it all together and found some severely sticky spots in places. So, I've got some checking to do.

One thing I found is that the frame had spread on the crankshaft end when I milled out the center opening.






I'm wondering if there is a way spring it back without breaking it. Since I had bored the crankshaft hole before milling the opening, the holes are now sprung out of aignment, but I don't think that's a problem When I insert the bearings and crankshaft, it turns over freely enough. I wounder if I could get by with just milling the outside surfaces flat?

Chuck


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## maverick (Aug 4, 2011)

Chuck,
Use a gage block stack or adjustable parallel in the slot to guard against over bending, and squeeze the ends together untill 
they're straight. When you screw up as many parts as I have, you have to get good at fixing them. Great looking engine.

Regards,
Mike


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## mzetati (Aug 5, 2011)

Chuck,

I'd put it lenghtwise into a vice (only to have it aligned again) when fitting to the base: the four screws should keep it aligned an no one will ever know.
I'd scribe a note on the underside of the base, to remind me to put it into a vise again, if servicing will be required.

Marcello


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## cfellows (Aug 5, 2011)

maverick  said:
			
		

> Chuck,
> Use a gage block stack or adjustable parallel in the slot to guard against over bending, and squeeze the ends together untill
> they're straight. When you screw up as many parts as I have, you have to get good at fixing them. Great looking engine.
> 
> ...



Thanks, Mike, that's what I did. I hadn't used gage blocks before an that does help. I used stacked feeler gauge blades and kept removing one, then bending, until I got it where it needed to be. Now everything goes together nicely. Seems that cured all my alignment woes.



			
				mzetati  said:
			
		

> Chuck,
> 
> I'd put it lenghtwise into a vice (only to have it aligned again) when fitting to the base: the four screws should keep it aligned an no one will ever know.
> I'd scribe a note on the underside of the base, to remind me to put it into a vise again, if servicing will be required.
> ...



Good idea, Marcello. I would have probably used your method had I not already gone with Mike's advice. 

Chuck


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## cfellows (Aug 5, 2011)

Well, still a ways off from completion, but it runs! And it runs good, quiet, and solid.

For all you steam buffs out there, I finally get it! There is a whole new level of satisfaction from building an engine that is designed to power something, to actually do some work. I think I'm going to have a lot of fun with this project. Can't wait to get the engine finished and start planning the boiler.

Oh, yeah, and I guess I ought to figure out what I'm going to power with it. Still leaning toward some kid of land vehicle. 











Chuck


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## ironman (Aug 5, 2011)

Chuck, you whipped that out pretty quick. Looks good. Can we see a video with sound soon?

Looks like you changed the Crank shape some and the lower cylinder cover doesn't have the strap bolted on. Are those some of your mods?

Good job. Thm: Thm: What type of land vehicle have you thought about?

ironman (Ray)


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## kustomkb (Aug 5, 2011)

That's a really cool looking engine Chuck.

Nice work!


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## cfellows (Aug 5, 2011)

ironman  said:
			
		

> Chuck, you whipped that out pretty quick. Looks good. Can we see a video with sound soon?
> 
> Looks like you changed the Crank shape some and the lower cylinder cover doesn't have the strap bolted on. Are those some of your mods?
> 
> ...


Thanks, Ray. I'll put together a video once I get the engine mounted on a base. Right now I have to hold in my hand to run it, while also holding the air tube on the fitting so it doesn't blow off!  

The crank's shape is a little different... mine was easier for me to machine than the drawing. Instead of packing on the bottom of the cylinder, tightened by two screws and a strap, I machined a two part bottom with an o-ring in the middle. For a land vehicle, I'd really like to build a tank or a caterpillar, but I'm stumped on how to make a suitable set of metal tracks. Maybe something like a 4 or 6 wheeled crawler. It'll be some kind of off-road vehicle, slow but powerful.



			
				KustomKB  said:
			
		

> That's a really cool looking engine Chuck.
> 
> Nice work!



Thanks, KB.


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## Maryak (Aug 6, 2011)

cfellows  said:
			
		

> I'm stumped on how to make a suitable set of metal tracks.



Chuck,

Very Nice engine. :bow:

How about bike chains side by side or a drive chain with more than one sprocket.................just a thought, (I know..........it's a dangerous pastime).

Best Regards
Bob


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## SBWHART (Aug 6, 2011)

Good job Chuck it really does look a powerful engine . 



> but I'm stumped on how to make a suitable set of metal tracks. Maybe something like a 4 or 6 wheeled crawler.



You could use a toothed timing/drive belt for a track you can pick them up quite easily along with the sprockets, just google timing belt.

Stew


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## bezalel2000 (Aug 6, 2011)

Hi chuck

 Nice machine  Thm:



			
				cfellows  said:
			
		

> I'd really like to build a tank or a caterpillar, but I'm stumped on how to make a suitable set of metal tracks.
> 
> Thanks, KB.



lament the good old days! when model track links came on the tops of beer cans. :big:

Now you throw them away with the can. :

Bez


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## steamer (Aug 6, 2011)

Hey Chuck

Nice engine!  you'll love the sound it makes when it gets down to work and puts forth a nice "bark" out the exhaust....I always love that sound.

 :bow:

Dave


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## Blogwitch (Aug 6, 2011)

Chuck,

I can give you a rough idea of the size of boiler required. I ran mine on a 3.5" diameter x 4.5" (approx) water filled area vertical boiler heated by gas from just the bottom end, thru about eight vertical tubes that kept the engine running continuously, engine regulated at 20psi with the boiler blowing off at 45psi continuously. One about the same size would be perfect for yours. As I have said before, they are not designed to be a fast running engine, but one with oodles of low end torque, so steam consumption is rather meagre compared to the modern day commercial 'square' engines that run a lot faster. A well regulated boiler of that sort of size should keep you steaming for around 30 to 45 minutes, maybe even an hour. I can take some piccies of the boiler if you need an idea of what to aim for, it is still sitting in the back of my shop.

I would recommend doing the horizontal engine layout though (even if you have it standing upright), with the double output shaft (much better for a land based vehicle). The way yours is built is to drive a single prop shaft in a boat. The flywheel is not necessary, and a 3 to 1 or 4 to 1 reduction would be ideal (mine is 3 to 1). I reckon even my smaller one at 20psi would be able to haul around 20 to 30 lbs in weight quite easily.

I hope this helps a little


John


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## cfellows (Aug 6, 2011)

Maryak  said:
			
		

> Chuck,
> Very Nice engine. :bow:
> How about bike chains side by side or a drive chain with more than one sprocket.................just a thought, (I know..........it's a dangerous pastime).
> 
> ...



Thx, Bob. I've seen posts about using link changes and bike chains. The hard part is you still have to attach some kind of plates to the outside.



			
				sbwhart  said:
			
		

> Good job Chuck it really does look a powerful engine .
> 
> You could use a toothed timing/drive belt for a track you can pick them up quite easily along with the sprockets, just google timing belt.
> 
> Stew



Thx, Stew. I hadn't thought of using timing belts. I would really prefer metal tracks if possible. However, the timing belts are a good option if I fail to find a metal solution.


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## cfellows (Aug 6, 2011)

Bogstandard  said:
			
		

> Chuck,
> 
> I can give you a rough idea of the size of boiler required. I ran mine on a 3.5" diameter x 4.5" (approx) water filled area vertical boiler heated by gas from just the bottom end, thru about eight vertical tubes that kept the engine running continuously, engine regulated at 20psi with the boiler blowing off at 45psi continuously. One about the same size would be perfect for yours. As I have said before, they are not designed to be a fast running engine, but one with oodles of low end torque, so steam consumption is rather meagre compared to the modern day commercial 'square' engines that run a lot faster. A well regulated boiler of that sort of size should keep you steaming for around 30 to 45 minutes, maybe even an hour. I can take some piccies of the boiler if you need an idea of what to aim for, it is still sitting in the back of my shop.
> 
> ...



Thx, John. I do like the horizontal version of the engine and am leaning in that direction. If I do a wheeled vehicle, as opposed to tracks, I'll have to figure out some kind of differential. And, if I do tracks, I'll have to figure out a dual clutching mechanism.

As to the boiler, I'm favoring a horizontal, single flue design as of now. I'd like to keep the amount of silver soldering to a minimum. However, a picture of your vertical boiler would be worth considering.

Chuck


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## GailInNM (Aug 6, 2011)

sbwhart  said:
			
		

> You could use a toothed timing/drive belt for a track you can pick them up quite easily along with the sprockets, just google timing belt.



Timing belts are also available that are double sided with cogs on both sides. That would be a little more realistic than a smooth outside.

It might be possible to drill the outside cog length wise across the width of the tread and put a pin through to retain a metal tread plate. Two pins in each plate with the hole in one of them slotted to allow it to go around the wheel radius. 

Also look into the robotic web sites. There are a variety of tracks there in quite a few sizes for the robot builders. Some of the larger ones are quite expensive but the smaller ones are not too bad. Some of them sell individual track sections so you can make up what ever length you want. Most of those are molded plastic.

Gail in NM


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## cfellows (Aug 7, 2011)

At Bog's suggestion, I began making the base and gears for the horizontal version of this engine. The smaller pinion gear is integral with the crankshaft, turned from spur gear pinion wire, as it's called. It's a 9 tooth, 24 pitch gear in a 12" length which I had bought some years ago from stock drive products. Easier than trying to figure out how to fasten a pinion gear to a separate shaft!

The larger gear was made this afternoon from aluminum and has 36 teeth, 24 pitch, 14.5 degree pressure angle. This gives me a 1 to 4 gear ratio between the engine and the output shaft.







You can see a better view of the pinion wire in this photo...






Chuck


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## doubletop (Aug 8, 2011)

Chuck

If you are looking at a vehicle you may be interested in this video.


http://www.youtube.com/watch?v=1s9vQx7OvB4

If you look at the engine it resembles this design pretty closely, although it's a commercial job from Regner. No idea who copied who on the design but does it matter?

Pete


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## Brian Rupnow (Aug 8, 2011)

Now that is neat!! Makes me think of "Mad Max Beyond Thunderdome"!!!!----Brian


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## cfellows (Aug 8, 2011)

Yeah, I've watched that and other videos from the same guy a lot. I really like it, but I'm not sure I have the patience for that level of detail. Also, I think he used a Tamiya Monster Dump Truck for chassis, wheels, and other major parts. Those trucks retail for over $600 as near as I can tell. I'd like something that big, but it will probably be little more "Plain Jane".

Chuck


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## Brian Rupnow (Aug 8, 2011)

Chuck---There is a hobby shop near me that specializes in radio contolled models of all kinds. I have seen nylon "tank treads" and drive sprockets in clear packages hanging on the walls, and they appeared to be very economically priced.---Brian


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## cfellows (Aug 8, 2011)

Thanks, Brian. I've seen the plastic tread kits. I really want metal and preferably steel if I go with a tracked vehicle. Unfortunately, doesn't seem to be any simple or inexpensive solution.

Chuck


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## cfellows (Aug 8, 2011)

Here is the venerable video of my first run. The engine's got a sticky spot, but I think it'll work itself out with a little run in.

[ame=http://www.youtube.com/watch?v=9E2MZfIQNBk]http://www.youtube.com/watch?v=9E2MZfIQNBk[/ame]

Chuck


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## moanaman (Aug 8, 2011)

Well done Chuck, 
it looks very nice and I think you are right that it will run in OK. Scaling up and changing dimensions does lead to a possible can of worms, but your experience has countered these possible problems. 

Barry G


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## steamer (Aug 8, 2011)

Chuck

That thing is going to pull like a mule!....Very nice

OK what version of Tank are you going to put it in.....I have Tank on the mind when I see that engine.

I think it's the gears..... ;D

Dave


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## kustomkb (Aug 8, 2011)

Congratulations Chuck.

Another beauty for the stable.

Great job!


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## Dan Rowe (Aug 8, 2011)

Chuck,
If you still need metal track do an ebay search of "metal tracks" a lot of toy stuff comes up in the $60 range and there are replacment tank treads for 1:16 scale tank treads in the $75-100 range.

Dan


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## ironman (Aug 8, 2011)

Chuck, that engine sure sounds strong. At 4:1 it should really be a puller. Go for it.

ironman (Ray)


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## Blogwitch (Aug 8, 2011)

Very nice indeed Chuck.

Stake it into the ground and fit a block and tackle and it should make a good stump puller.


John


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## cfellows (Aug 12, 2011)

I guess copper is the new gold. I'm now thinking about the boiler and I'm trying to find some 3.5" OD copper tube with a 1/8" (or so) wall. The closest I can find is at onlinemetals.com and they want $16.46 an inch or $156 for a 12" length of 3.5" x 3/16".  All the reasonably priced stuff is .065" wall which I imagine is not thick enough?

Any suggestions???

Chuck


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## Dan Rowe (Aug 12, 2011)

Chuck,
The prices are a little better if you go with a common copper pipe size of either 3" or 4".
The answer of is .065 wall thick enough depends on the working pressure.
http://www.plumbingsupply.com/copperpipe.html

Dan


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## Blogwitch (Aug 13, 2011)

Chuck,

Sandy, a member from many moons ago used to make boilers for a living, and he actually put the drawings up on here for a 3" vertical, but it looks like one of the sheets is missing.

I do know that his 3.5" horizontal boiler used 16SWG (1.6mm or 0.064") for the main wall thickness and flange ends. If you go for the thicker wall tube that Dan mentions, that should be ideal if you want to scale up to 4" diameter

I hope Sandy doesn't mind, but I have attached the plans for his horizontal boiler. 

It is gas fired, but I have made loads of the burners and refillable gas tanks over the years and a man of your calibre should have no trouble making one. I won't give gas tank details as they can be dangerous if not made correctly, but if you send me an email, I will send you details of how to make one.

BTW, unless you are making your own boiler fittings, expect them to cost as much as the home made boiler, plus you may use up to about 50 bucks of silver solder wire to put it together, or maybe a bit more as the price is going up all the time.


John. 

View attachment ACS Horizontal Boiler.pdf


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## Blogwitch (Aug 13, 2011)

Chuck,

I may as well give you the full set of plans for the vertical one as well, just in case you want to go down that route.

John 

View attachment ACS Vertical Boiler.pdf


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## Maryak (Aug 13, 2011)

Bogstandard  said:
			
		

> Chuck,
> 
> Sandy, a member from many moons ago used to make boilers for a living.



John,

I used to be in fairly regular correspondence with Sandy but I have not received any replies for a while. Would you have any current information and if you do, would you be prepared to share it. ???

Best Regards
Bob


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## Blogwitch (Aug 13, 2011)

Bob, I have sent you an email.


John


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## Maryak (Aug 13, 2011)

John,

Received and Thankyou :bow:

Best Regards
Bob


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## crab (Aug 13, 2011)

Hi Chuck.I have some 3" type L you can have.If you want it PM me.
Crab


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## cfellows (Aug 13, 2011)

I would like to acknowledge and publicly thank Crab for generously offering me a length of copper pipe for my boiler. Very much appreciated...

Chuck


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## crab (Aug 13, 2011)

It will be on it's way Monday Chuck.
Crab


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## cfellows (Aug 18, 2011)

Received not 1, but 2 lengths of 3" copper pipe in the mail today. With an .080" wall, these will make a couple of very nice boilers. Thanks, Bill (Crab)!

Chuck


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## doubletop (Aug 22, 2011)

I did Sandy's vertical boiler here http://www.homemodelenginemachinist.com/index.php?topic=8687.0

All the sheets are in the downloads page and the missing sheet was posted latter. There is also the drawing for the burner the jets can be obtained from the Bruce engineering part of Polly Model Engineering

http://www.pollymodelengineering.co.uk/sections/bruce-engineering/index.asp

There is also a sheet for the safety calcs somewhere (it may be in the thread) 16swg, 0.065" tube is fine especially when you are only likely to be using this boiler at no more than 30-40psi (if that) as any more the port faces part and the efficiency drops off.

Pete


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