Moteur Oscillant - Double acting Oscillator Twin

[cfellows]

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

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.

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.

 

[cfellows]

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

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

 

[GailInNM]

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

 

[cfellows]

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

 

[doubletop]

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

 

[Brian Rupnow]

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

 

[cfellows]

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

 

[Brian Rupnow]

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

 

[cfellows]

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

 

[cfellows]

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

 

[moanaman]

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

 

[steamer]

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

 

[kustomkb]

Congratulations Chuck.

Another beauty for the stable.

Great job!

 

[Dan Rowe]

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

 

[ironman]

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

ironman (Ray)

 

[Blogwitch]

Very nice indeed Chuck.

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


John

 

[cfellows]

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

 

[Dan Rowe]

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

 

[Blogwitch]

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

 

[Blogwitch]

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