Cheap and Simple Steam Engine

Step 8: Finishing Up

Piston:
First make a 90° bend in the piston rod 20.5mm from where it enters the end of the piston. Now insert the piston into the cylinder, then simultaneously push the cylinder pivot rod and the cylinder rod through the body and the crankshaft respectively. You will likely have to turn the crankshaft to make the hole for the cylinder align with the bend in the cylinder rod.

Now you just need a way to hold the cylinder tight up against the body. I used a spring from a retractable pen held in place with a screw on "prop-saver" from a model airplane. I also found just putting an elastic band around the piston and body worked quite well... if not better than the spring, this option is also much easier to remove than if you glued a cap on the cylinder pivot rod.  An elastic or two should really be all you need here.

Air Supply:
Lastly you need to connect one of the top two holes on the flywheel side of the body to a compressed air tank or pump. To do this I just glued some plastic tubing to the body; just do whatever works best for you. This motor works quite well for me on ~15psi. Turn on the air and give the flywheel a quick flick and the motor should start, if not try flicking it in the other direction. If you line it up just right the motor will even start without you flicking it.  Switching which hole the air goes into will reverse the direction of the engine's rotation.

Troubleshooting:
If your motor does not run first make sure everything spins fairly easily when turned by hand. If it doesn't try figure out what is stopping it.  Next make sure that you did not accidentally get glue in any of the holes that supply air to the motor.  Lastly try running the motor on higher PSI.  Other than that there isn't much more I can suggest.  You can try posting any questions in the comments, I'll see what I can do but I'm no expert on the subject. 

Final Thoughts:
Over all I am very pleased with how this little motor came out.  It runs very smoothly, looks good and was really easy and cheap to build.  Some possible improvement include; the use of bearings to reduce friction, waxing the wood where it rubs together, or replacing/coating the wood with a layer of Teflon which would greatly reduce friction and help with the air seal. You might also try making the air input/output holes a little bigger and upping the PSI for more speed. 

If you have any comments, questions, or suggestions please don't hesitate to put them in the comments.  I'll do my best to respond to them. 

I hope you enjoyed my instructable and I wish you a successful build.

Comments

[woodstockbirdy]

Umm I Know this is kind of late to ask but the last steps you wrote but there are no pictures. I think you probably did that because you were already done. But I don't quite understand how the final assembly goes together. Could you please add one or two more pictures just to clear up. Thanks

[lost2010]

How is this a steam engine if you are using compressed air? this is a waste because its pointless to use a machine to run another machiine.

[fishhsifboy]

it uses the same principles as an oscilating steam engine so hence technically it is but as the maker said, a lot of parts are wood so if you want a genuine steam engine use metal.

[fishhsifboy]

it uses the same principles as an oscilating steam engine so hence technically it is but as the maker said, a lot of parts are wood so if you want a genuine steam engine use metal.

[Billgun21]

This is a steam engine, If you built a small boiler and everything to go with it it would run it just as well as the compressed air. But homemade boilers are risky and dangerous if you're not experienced. So using a air compressor is safer and easier (And cheaper)

[Everett_McKinley]

but not as cool besides the boilers don't generally burst like a frag, their seams split and vent steam. sorry if you wanted shrapnel but chances are you'd just get burned.

[steve-lane]

(removed by author or community request)

[liam2317]

In the final picture on Step 8 you can clearly see how the air hose (it's the clear tube which is connected to the white plastic tube by a smaller, black piece of heat-shrink) is connected to the motor. You will not need to drill any holes in the brass pipe.

[Sky Woulf]

if using seeam (bolier problems aside) you could use an old model airplane trick..... in a gas powered model airplane we coat our "wood" engine compartment and fuel tank compartment and the firewall with painted on 30 min epoxy (find it at your local automotive parts store) and this completely seals the wood from "Any" moisture, solvents, etc. (also has high temp restance somewhere around 1300 degrees F i think) so if you were to coad ALL surfaces of your wood like that you could (I think) run low presure setam in this motor. then you could try to run it off a stovetop tea kettle with a stopper and a hose. just allow for the pressure to build before starting!

[liam2317]

I think this would probably work quite well. If someone does try this I would definitely recommend coating the parts with epoxy either before, or as you assemble them (you could even use the epoxy coating to glue the parts together as well as seal them!).

[sbinc028]

what's the spring for?

[liam2317]

The spring is used to push the cylinder head piece up against the main body piece to provide a good tight seal between the two. In the pictures though, you can see I replaced the spring with a small elastic band that goes around the whole steam engine. The elastic seemed to work a lot more efficiently than the spring did.

[DehLeprechaun]

first how would i hook up steam to it? second is it possible to hook 2 or more to one crankshaft? and third do you think it would work for a boat or car propeller/wheel respectively? thanks

[liam2317]

Unless you know what you are doing a steam boiler can be rather dangerous, even a miniature one. Be sure you do your reading and use the proper safety precautions if you do build one. Hooking up steam would be quite easy, just attach your boiler to the same port that the compressed air would normally be attached. As noted in the instructable using steam with an engine made primarily of wood will cause warping/swelling problems so replace with wood parts with something like aluminum. You should be able to add pretty much as many cylinders as you want, you probably wont get much more speed but you should get lots more torque. I think that this motor would definitely work in car or boat... or train. I am planning to eventually build one with twin cylinders using aluminum and putting it in a small remote control boat.

[riverreaper]

R/C Steam Turbine Tank is post in this sight

[DehLeprechaun]

i was thinking of making an rc boat/car using your method. torque was wat i was looking 4. one cylinder doesn't seem very strong.

[liam2317]

I think it depends a lot on how much your car/boat ends up weighing. As David97 mentioned adding gears to the motor to slow the output would be highly recommended, at least with a car. You might be able to get away without gears for a boat.

[David97]

You could try adding gears to the engine for more talk.

[Beergnome]

actually for a motor like this direct drive is just fine for a boat. for a car, a small spur on the fly wheel to a large sprocket on the Axle should work fine. just keep in mind that this type of engine is not self starting. hey liam? when ya gonna get that drill press going and make an updated one in metal? ;)

[liam2317]

I discovered that this engine will self start if you align the intake port with the cylinder's port before turning on the air... no flicking required, so it's kind of self starting. If you had a two cylinder version you could probably make it really self starting. WAY too busy with school right now to design/build anything. Hopefully some time in late August when I'm done school I'll be able to find the time to make one. A lot of other side projects on my plate right now though!

[riverreaper]

how do u stop it ?

[liam2317]

Simply disconnect it from the steam/compressed air supply. Pretty easy. :)