# Thinking about a radial steamer



## Brass_Machine (Jan 3, 2008)

Thinking about building a radial steamer... I played around with Elmer's radial design (#11). What do you think? I may make the heads a little taller just so I can add cooling fins to them (for look ofc)







Cheers
Eric


----------



## Powder keg (Jan 3, 2008)

Looks nice. If you got tricky, you sould hide the head bolts and the air intake with the cooling fins. Dome the top of the heads a bit would look nice also. 

Wes


----------



## Brass_Machine (Jan 3, 2008)

Wes,

I thought about hiding them. but I kinda like the exposed 'look at me' aspect. One of the main reasons I changed elmer's design a little.

Cheers

Eric


----------



## BobWarfield (Jan 3, 2008)

More cylinders! More speed!

Captain, dewn't noo how much longer she'll take it!

Scotty I need more power!

Sorry, fellas. Returning to our regularly scheduled thread now...

Cheers,

BW


----------



## Bogstandard (Jan 4, 2008)

Here is one I did, many moons ago. It was made from ali and cast iron castings.
It stands about 4.5" tall and is one of the smoothest running engines I have ever built. On full wack at 60psi, except for the exhaust note (which sounded like a muffled ic engine)you had to touch it to check it was running.
It is designed to run in one direction only, but that big brass monstrosity hanging on the back is my own design of speed control, but also gives it the fwd/rev capability.

The castings will be made available again from here, eventually.

http://www.hemingwaykits.com/acatalog/shop.html

















John


----------



## Brass_Machine (Jan 4, 2008)

John,

That's pretty cool looking.

Looks kinda similar in ways to Elmer's radial...

Eric


----------



## Bogstandard (Jan 4, 2008)

The internal layout for the conrods is slightly different, plus the front end is ballraced, so allowing an overhung flywheel. Other than that the engine operates on exactly the same principle.
If you are going to make one, the critical area is the rotary valve on the back end, too sloppy a fit and it will run like a bag of nails, too tight and it will tend to lock up. That was the problem with mine, when run on live steam, because of the different expansion rates of the different materials, it would tighten up. A fair amount of stripping down and hand lapping was required to get the perfect fit, eventually a very good compromise was reached, 0.0005" was the difference between locking up and running smoothly. But if only ever running on air, this problem shouldn't arise.

John


----------



## cfellows (Jan 4, 2008)

I've also been thinking about a 3 cylinder compressed air engine using my poppet valve design. I'm also thinking about using a half speed, geared cam to the engine pistons would be pressurized every other revolution like a four stroke engine. I still haven't decided whether to make the engine with overhead valves or F-head design.

Chuck


----------



## Bogstandard (Jan 4, 2008)

Chuck,
I am sure you would enjoy a rotary engine like this, no matter which way you feed the pistons. They are so smooth running.

I do have the plans for a small three cylinder rotary that uses flats on the crankshaft for the timing and is fairly easy to make. Mine was made many years ago and has just been rooted out of storage and stripped down for a facelift. If anyone is interested you could email me and I will send you the plans. I can't post them because of copyright issues.
The cylinders are made from K&S brass tube, but I beefed mine up a bit. If you want a piccy I am sure it can be arranged.

John


----------



## Brass_Machine (Jan 4, 2008)

John... PM sent


Eric


----------



## deere_x475guy (Jan 4, 2008)

Piccy...piccy....we like piccy's ;D


----------



## Bogstandard (Jan 4, 2008)

Ok, but it will have to wait until it gets light here, it is just after 4.30 am.

John


----------



## Brass_Machine (Jan 4, 2008)

4:30 am? ??? ?

John, you either get up waaay too early or go to bed waaay too late ;D

Eric


----------



## Bogstandard (Jan 4, 2008)

Haven't been to bed yet, I am now going to try and get a couple of hours ZZZZZ's

John


----------



## Bogstandard (Jan 5, 2008)

Here is what it looks like when made, a fully controllable fwd/rev radial engine, designed to push a model boat along.






And here is mine, stripped down for refurb. Very few parts indeed.
There are a few things to point out on mine that might be relevent.
You will notice that I have fitted viton piston rings, don't bother, on an engine this size it just causes problems with friction.
I have made much thicker walled cylinders, this was because when I dropped the first one I made, one of the cylinders easily dented and so the engine was scrapped, as it just would not run on two cylinders.
The major mod, which I think is essential, is if you look at the cylinder head on the one at the front, you will notice a bolt in there. Rather than cutting the line to the cylinder and putting a piece of silicone tube on it, this allows you to time the engine much easier, and looks better as well.
As usual I silver soldered mine, but the plans called for soft soldering. I reckon this engine, if only going to be run on low pressure air could be made mainly out of ali and stuck together using a Loctite engineering adhesive.
It runs on a breath of air (5 psi) if made right, but I have had it on 60psi wet steam and it really motors along.






I must root thru all the other old boxes in storage to see what I can find.

BTW this is the sort of job that requires an easy tube bender, again I have plans and used in conjunction with Bob's groove cutting tool could easily be fabricated. Usual thing, send email.

John


----------



## deere_x475guy (Jan 5, 2008)

Awh..thats better....pics ;D
Looks like and interesting engine John. Looks like it is mostly brass...I sure wish I could get my hands on brass....it's so dang expensive now. I have a pretty good supply of crs, aluminum and O1 drill rod.

I was working on Mcguyver's bender last building the base plate and couldn't believe how late it was. I'll post pics once I am a little farther along.


----------



## Brass_Machine (Jan 5, 2008)

deere_x475guy  said:
			
		

> ...
> I was working on Mcguyver's bender last building the base plate and couldn't believe how late it was. I'll post pics once I am a little farther along.



Look at Bob go! He is my inspiration as of late... A tube bender, a radius cutter, twin engine... when does this man sleep? ;D

Must get in the shop


----------

