Cheap and Simple Steam Engine

The Idea:
Recently I saw a video of a remote controlled boat powered by a miniature steam engine  and was instantly hooked on the idea.  After doing a bit of research I found miniature steam engines cost hundreds of dollars or require some very advanced skills and tools to build.  Yet looking at the actual mechanism which allows them to run they are really quite simple so I decided to try and make one on the cheap. 

The point of this project was really to see how cheaply and easily a miniature steam engine could be built. I built this engine in one day and for under $10 in materials so I think it's safe to call it a success.

This engine is 7.2cm (2.8") tall.

Some Things to Note:
First off I should state that this steam engine is only a steam engine.  This instructable does not include instructions on how to build a boiler to produce steam.  Instead I run the steam engine on compressed air.  If you don't have a compressor a bicycle pump works well too, it's just a lot more work for you.  ; )

I should also note that even if you did build a boiler this engine probably wouldn't work well because many of it's major components are wood.  In the presence of steam the wood would swell and warp causing problems.  A simple solution to this problem would be to replace the wood parts with aluminum ones.

I am a very visual teacher so be sure to read the 'Image Notes' (hover your mouse over the yellow boxes on the images), it will likely make my instructions clearer. 

How it Works:
You could read my lengthy description below or you could check out the totally awesome animation by the guys over at www.animatedengines.com, find it here! I should note that this animation is of a "double acting" engine, in that is has ports on both the bottom and the top of the cylinder where mine is a "single acting" engine with ports just on the top.  This just means that the engine relies more heavily on the momentum of the flywheel to keep it running but is a lot simpler to build.

This type of engine is called an Oscillating Steam Engine.  If you watch the video below you will see that the cylinder on this engine actually moves back and forth as the flywheel turns (it oscillates!), this action is what opens and closes the ports which let compressed air enter the engine and exhaust air leave. 

The cylinder has one port at it's top which is pressed up against the main body of the engine.  The main body on the other hand has two ports, one for the compressed air and one for exhaust.  As the cylinder tilts to the right it aligns with the compressed air port allowing air to flow into the cylinder and push down the piston.  This causes the crankshaft to turn, thus tilting the cylinder over to the left and allowing the air to exit the cylinder though the exhaust port as the piston comes back up.  Then the process repeats. 




View on YouTube

Step 1: Materials, Tools, and Plans

Most of the materials and tools for this project you will likely already have around the house.  The only things I had to buy were the brass tubing, tubing cutter, and some wire. 

Materials:

• 3/16" Plywood (aprox: 12x8cm)
• Retractable Pen (optional)
• Brass Tubing: (find some at your local RC hobby shop)
            13/32" for the piston and 7/16" x 0.014" for the cylinder
• "Tea Light" candle
• Heavy washers with a diameter less than that of the tea light
• 5 Minute Epoxy Glue
• Plastic Tubing (to connect your compressed air supply)
• HomeDepot sprinkler marker flags or piano wire (~18AWG)
• Floral stem wire or piano wire (~24AWG)
• Q-Tips with plastic tube (not paper)
• Small elastic bands
• Plastic Wrap

Tools:

• Drill (or better yet; a drill press) and bits
• Tubing Cutter ($5) - you should also be able to find one at most hardware stores.
• Pliers and Wire Cutter
• Empty Tin Can
• Razor Knife
• Sandpaper
• Vice (optional)

Plans:

Attached are two PDF files.  "Parts Only With Measurement" includes a layout of all the parts you will need to cut out of wood as well as the lengths for the wire and brass tubing parts.  "Parts Only No Measurements" is exactly the same but without any measurements printed on the page; good for cutting out and gluing to your wood as a guide. 

Some people are having trouble opening the attached PDFs, if you are too try the links below. 

If you can't open the link to the PDF; here is a direct link to it.
If you still can't open the PDF; here is a link to a high resolution PNG image of the plans. 

Comments

[patrickpow]

Will it matter if the copper tubes are bigger diameter and height wise than those you showed.

[liam2317]

I actually used brass tubing for this little engine, I bet copper will work fine too though so long as they fit together very closely and still move freely. The diameter really shouldn't matter much (within reason) so long as there is still a very close fit between the two. Height wise; unless you scale the other parts you will run into problems. Just make everything bigger to match the scale of your tubes and everything should work great.

[Kevin12345]

Digging in my old broken VCR i found the video head and the first thing that popped into my head was "flywheel". just a thought..

[Bilal k Abbasi]

nice one .....:-)

[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.

[MIRAMANALI]

hi this project looks really cool i am planning to use the basics to make one for a geared bicycle so that i can use its gears as helping hand for the engine(reducing the load). instead of a single acting engine i want to make a double acting engine but am confused whether adding one more inlet and outlet as above hole on bottom side of the plank will do the job? ,sealing the cylinder from bottom of course with the valve u have shown above and running the piston rod through the plank of that valve (the hole will be lined inside with rubber just to prevent air leaks because of piston rod)

[egustys]

Best way using propseivers (last foto)

[Daniel Deacon]

you could also use a hacksaw but that might be abit more trikey and not get such a good finish

[akidrick]

how did you cut the ply wood

[Daniel Deacon]

cut the ply with a saw. cut roughly around where you need to cut. make sure you have drawn out the patten onto the wood exactly right then make a waste line and the exact line cut in the middle of the waste line and the exact line when this is done sand it down till it is perfect. make sure you don't go over the exact line or you will need to start over. it would be good if you used a small saw unless you are very careful. you could also use a copping saw or jigsaw but that might be abit more tricky

[sam D]

Love this build. White nylon cutting boards from the junk shop - which are high density PE might be an alternative for the wood. Low friction, good durability and high temp resistance.

[planetroverrobo]

I'm thinking about building a steam powered boat. And I like the idea of this steam engine but my idea of a engine is where there is olive oil burning boiling 2 quarts of water. when the steam becomes pressurized it will be pushed out of a two way valve so it creats pressure to push boat. But this engine has to carry a model boat, car battery, live camer, antena for radio control, ROV (which has camera on it), 200ft cable to power ROV, 200ft cable to carry information from ROV camera to model boat. Which engine would be better the one I thought about or the one liam2317 made?

[liam2317]

Sounds like a pretty complex project already, may as well save yourself the trouble and just go electric. You would need a pretty big steam engine to move around all the things you listed at a decent speed. Unless you have a very specific reason for using a steam engine I would definitely just use an electric motor if I were you.

[planetroverrobo]

ok thanks. I'v decided to go electric any ways also I'v decided to take everything of what I listed. Instead I made a pontoon boat puting 4 D cells or C cells and a small solar panel to rechage batteries. Thanks anyways though

[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.

[steve-lane]

(removed by author or community request)

[liam2317]

You can download the PDF attached to Step 1 which is titled "Parts Only With Measurements.pdf" or you can get them from the attached image of the plans.
Here is a direct link to the large image of the plans.

[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.

[flowerman7]

Nice project! for the piston could you cast it out of J-B weld like many people do when building stirling engines. How airtight doues the pison and cylinder actualy have to be? Thanks

[liam2317]

I tried casting a piston out of epoxy as well but found that the brass tubes fit much better, were much easier to make, and seemed to have a lot less friction. My guess would be that it would still run if it leaked a bit but the more air tight the better!

[David97]

I have been talking to my teacher who has done a night course on building a steam engine. I have made 2 double acting engines to put on a model train.
I was going to run it with a boiler and a RC system. The boiler was going to be designed like a real one. Here’s what I thought of doing.

[David97]

I fogort to say the two engines would have a shaft between them to stop the steam taking the easyst route and olny going in circles

[GillesBathory]

the 2 pdf's "Parts Only With Measurements.pdf" and "Parts Only With no Measurements.pdf". The links dont work, how can i get them ?

[henrib736]

How many psi's does this run on?

[liam2317]

See the last step under the heading "Air Supply" for more info, but it runs well on ~15PSI.

[fuzzyguy]

The valve is tge 2 pieces of wood. as the piston is tilted by the crankshaft to the power stroke side it's 1 hole lines up with the hole conected to the air supply. As it passes by the bottom of it's stroke the 1 hole startes to line up with the other hole in the back piece. This hole allows the air to escape as the piston comes up. The spacing of the holes on the back piece are all important to how the engine runs.

[riverreaper]

could you vent the escapeing air in a way that it flicks it to start it ? sorta like the air compressor large in air to a fine out , simmlar to how they jet air to cut with only not that fine.

[liam2317]

I bet you could, maybe making some kind of little steam turbine like device could do it... hmmmm good idea!

[liam2317]

Thanks for the great description!

[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. :)

[jam BD]

It's kind of cute =)

[liam2317]

Thanks! : )

[riverreaper]

i bet you spent more time answering qwestions than it took to build it

[FuzzyStefan]

hey! sweet project! if you made it bigger and had a few more cylinders, do you think something like this would be able to power a small bike/car? great job man, -Fuzzy Stefan

[liam2317]

To be honest I'm no physicist and this is the first engine I have built, but I don't see why it wouldn't work. You would likely do better building it out of metal though, or perhaps using a lot of fiberglass to reinforce the wood it might work. Fiberglass would be good too because it would seal the wood and keep the wood from warping or swelling if you used steam instead of compressed air. One nice thing about steam engines is that they are much quieter than internal combustion engines. As such a bike with a steam engine would be very fun to ride.

[FuzzyStefan]

thanks! I'm not very old [truing 13 soon] but already i can see that my generation is gonna have to figer something out an alternative to gasoline. and power to wait, steam is better thane electric, and if you had a electric boiler, it would be a self contained system, lots of out-put for little or no input. not to mention it would be a lot safer that either gasoline or electric. well any how..... thanks for your instructibul and advise! -Fuzzy Stefan

[liam2317]

Well there are a few things wrong with your comment... First off power-to-weight wise steam is terrible compared to an internal combustion engine, remember that you have to include a boiler in the weight of the system. This is why there are VERY few steam powered airplanes, the only ones ever built were really just proof of concept and didn't fly too well. Though I'm not 100% sure of this I would also guess that an electric system also has a better power-to-weight ratio than steam... depending on what type of batteries you use. If you are using an electric system to boil your steam you would definitely be a lot better off just using an electric motor. A LOT of energy is lost through escaping heat in a steam engine making it pretty darn inefficient (like less than 10% efficiency for a simple engine). I'm positive that a hydrogen fuel cell powered electric system would have a better power-to-weight ratio than a steam engine (as opposed to a battery powered system). It's true an electric system would be nicely contained... but this >"lots of out-put for little or no input" is totally wrong... You are never going to get more energy out of a system than goes into it. You need to do some reading on thermodynamics, namely the first and second laws. Lastly there is no way that steam is safer than electric or gasoline powered engines! You have a giant boiler filled with highly compressed scalding hot steam just waiting to explode and disfigure you... not to mention the boiler uses external combustion which is quite dangerous as well. Electric/Hydrogen Fuel Cells are the way of the future if you ask me.

[riverreaper]

what about usen solor to heat the stem that would take alot of the size down an then you could have your engine run from eletric an or stem an if you had an air compressor added to the mix that could get filled off the leftover an or even as you motored down the road also if you didnt worrie about anyone running into u fiberglass would work well with aluminum frame for your ride , corce theres the tinny problem of were the groshries would go :O)

[David97]

TRUBBLE GLUING STEP THREE? I am making this and I am almost done. But my piston was too small and fiddley to fit foam into it (steep 3). Instead I hung the piston rod wire from the garage roof just out of reach of the table. Then put my piston tube around it filled it with aproxy and let it set. I found it made things easyer and might be a easyer way for people who are having trubble gluing.

[liam2317]

Thanks for the tip! I will add it to the instructable. Let me know how your engine turns out! :)

[marz95]

Yes, could you please post the dimensions of the parts, for I too can't open the pdf file. I would really love to build this. Thank You.

[liam2317]

The PDF file really is the best way to go because it insures that everything will be to the correct scale if you print it, so try use it if you can.  If not here is a link to the plans as a 100dpi PNG image.  If you do print it be sure that the scale at the bottom of the page is correct. 

[marz95]

Well, I am a member just not a pro and it says you have to be pro to open it. Thanks for the plans.

[bugjojo]

I am trying to build this, but I can't open the pdf file, for I am not a member. Could you give me the dimensions for the wood pieces? Thanks!

[liam2317]

Don't you have to be signed up to leave comments?? If not you should really consider signing up, it's free and you will get a lot more out of the instructables here!

The PDF file really is the best way to go because it insures that everything will be to the correct scale if you print it, so try use it if you can. If not here is a link to the plans as a 100dpi PNG image. If you do print it be sure that the scale at the bottom of the page is correct.

[NitroRustlerDriver]

Very nice. In high school in a senior projects class, the final project was to create a steam engine. That ended after a boiler made from a soup can exploded and launched a kids steam engine at him and across the room. He was ok with only some minor burns, but no more steam engines after that, which of course was the year before I got to make one.

Then in college I created all the plans for the steam engine in the picture. ~15 parts and only 3" tall. Has a 3/4" bore. Never actually made it though, ran out of time. Maybe in the future.

[liam2317]

I wish I got to do an awesome project like that in high school, I can see how it could be a bit dangerous though. Running it on compressed air is much safer though... don't have to worry much about exploding boilers full of scalding hot water. That's always a plus! ;) Glad your classmate was okay! That looks like a very nice little engine. I hope you find the time to build one, I'd love to see it running. Thanks for sharing!

[Tombini]

I recently made a compressed air engine as part of a engineering course at school, got it running around 6000 RPM at 600Kpa. It was a bit more work since it was a full design process and made out of stainless steel, brass and other bits. I could upload some of the 80 pages of write up here if you would like :P

[liam2317]

Hehe thanks but I think that would kind of defeat the purpose of keeping this as simple as possible. :P I should look up how to measure RPM and see what results I'm getting with this motor. Definitely not 6000.

[Tombini]

You can either buy an expensive laser tachometer, or construct a bunch of shafts etc to gear it down to a readable level. I can't imagine this thing doing 6000 revs just by the fact that it would explode! :P This is really a good project, have you considered adding bearings or disposing of the flywheel? These are just two of the things that significantly decreased the output of my engine. Anyway good work.

[liam2317]

Looking around I found another simple way to measure RPM. Not as accurate perhaps but at least it will give my some idea of what kind of results I'm getting.  

If you look at the final step under the heading "Final Thoughts" I have actually included a few suggestions for making this engine more efficient, bearings are one of them.  Is it possible to run an engine like this without a flywheel?  It seems like it would need at least 2 pistons, or air ports on the bottom of the cylinder as well to run without one.

Thanks!

[Tombini]

My design incorporated duel radial pistons but only improved the torque produced and reduced its RPM. With a single piston it would run fine on 50ish Kpa at around 600 RPM without a flywheel. Eventually I will put some pics up and if you want I can send you the write up (beware it's around 80 pages) which has very detailed analysis of every aspect of the project.

[liam2317]

Sounds like a very interesting project! I would love to see pictures and read your write up. I'm sure it would be of interest to anyone else who would like to build this engine too. Thanks again!

[beff50]

lol, thats neat

[liam2317]

Thanks, glad you liked it!

[stringstretcher]

my version... a little bit different. I will have to try yours now! nice work http://www.youtube.com/watch?v=XHPz3rcreKQ

[liam2317]

Very nice engine! It looks like yours has a lot more speed than mine. Perhaps I need to make my ports larger as after ~15PSI more pressure doesn't seem to make it spin any faster where as yours just keeps going faster and faster. Hmmmm.

[Phil B]

I am unclear on how you open a valve or passageway to let air into the cylinder and then close it, as well as how you open a valve to exhaust the air at the bottom of the power stroke and then close it. It seems any engine would need to do these things.

[liam2317]

This type of steam engine is called an Oscillating Steam Engine. If you watch the video on the intro page you will see that the entire cylinder block actually pivots back and forth as the crankshaft turns. Because there are two holes in the body of engine on the power stroke the cylinder aligns with the air intake hole and on the exhaust stroke the air is let out through the other hole. Here is a great animation and description of how this type of engine works, the only difference being this engine has valves at both ends of the cylinder and mine only has them at one. 

Thanks for pointing out that this instructable really needs an explanation as to how this type of engine works.  I'm going to add it right now! 

[Phil B]

Thank you for the explanation. I thought that was probably the system you used for intake and exhaust, but did not have the proper names by which to inquire more exactly. Decades ago in the USA there was a book in our local library by Alfred P. Morgan. The title may have been "Mechanics for Boys." I remember plans in it for a steam engine, but it used pushrods and bell cranks driven by the flywheel to open and close a sliding valve.

[Nerdz]

It would be cool to see how much power (electrical power) if you used a Stepper motor (or some other motor) in place of the flywheel to act as a generator. Very interesting Technology :)

[liam2317]

Because this motor only has one piston you really need the flywheel in order to keep it running. However it would be easy to attach a stepper motor to the fly wheel. Just extend the crankshaft wire so it goes through the flywheel and you would have an excellent attachment point.

[nieks]

I agree with Phil B. Also: You probably used some sort of steam engin plans, which you adapted for this purpose. Could you tell us the source of the plans you based this on.

[liam2317]

You are right, this engine is an oscillating steam engine which is actually a pretty well known design. If you do a Google Search for "oscillating steam engine plans" there are lot's available but they are all meant to be machined from metal. I looked at many different designs while making this engine and also did plenty of experimenting on my own with different piston rod lengths, cylinder lengths, and what not.