MM-5 Coffee Cup Engine Kit
In stock (14 available)
- Stirling Engines
Ready to assemble. You only need to purchase superglue and silicone sealant. You will also need a few common hand tools to assemble your engine. It’s a pleasant two or three evening kit and a fun way to learn about Stirling engines. Click here for a video clip. If your computer can run Flash you may enjoy a Flash animation of this engine.
You may also want to buy a Spare Diaphragm. This is the only wear part in the engine.
The United States Naval Academy once had all of their mechanical engineering students build one of our kits.
If you want a very easy to build kit, we recommend this electric motor kit.
I enjoyed building my first MM-5 so mush that I bought 4 more and gave them to my friends as gifts. They all loved them and they are going strong.
Assembly was easy but for one point - the fitting of the rubber tubes to the piston and displacer rods. I found making the 'sock' roll difficult, especially on the piston rod, where I was worried about causing damage to the delicate diaphragm. It ran on a cup of hot water at the first attempt. Getting it to run on ice cubes took a bit more effort but I succeeded with the help of some salt to depress the melting point. Thank you. I am well satisfied with the little machine, which will amuse some people and amaze others. George Henderson St Albans, England
I've just built my coffee cup engine and it ran the first time! After all the horror stories I'd heard about non-working Stirling engines this was great, but even better, it runs on the heat from my hand! Not fast but it ticks over and is a real talking point. Many thanks for a great kit. Alistair Grant Carnoustie Scotland [Alistar has done an excellent job of assembling his kit! Running on the heat of your hand is not guaranteed. For suggestions from other builders on how to build a great MM-5 kit, read our model engines bulletin board. -- Editor]
The kit was very easy to put together, minimal modifications needed. It ran after the first spin for 45 minutes, the water in my coffee mug had cooled off. I replenished the hot water and it is off and running now. I also notice it does not run at a constant rate but speeds up and slows down from time to time. Next I will try the ice chip heat sink trick after it stops. [Please read Kevin's assembly tips in the model engine forum under the heading, "Assembly Tips for MM-5 - ed]
* * * * * Five Stars for sure! When my MM-5 arrived I could not wait to get started putting it together. The hardest thing for me to accept is that glue won't dry any faster by watching it. I guess I waited long enough for the glue to dry because as many others have said, my MM-5 ran the first time I tried it, and it ran even better after tweaking the displacer & power piston rod lengths. The cup I use is a QT (Quick Trip) 32 oz insulated drink cup filled with boiling water. I have had runs over three hours. Like the energizer bunny, it just keeps going, and going, and - - . The only lube that I have used is graphite. (I rubbed a pencil on the crankshaft cams & main pivot points.) I think I'll try a drop of machine oil on the displacer tube to slow down what little pressure bypass that there may be. At this point it has not run on heat from my hand. Maybe if I put my hand in boiling water first. (Kids, don't try this at home! - Adults only!) Randy
The good news is that I built it in about 2 1/2 hours yesterday and it worked perfectly first time. I think it's just a case of following the instructions carefully and being careful not to damage the parts, especially the piston membrane.
I've finally put my kit together. It's very cool and has upset some people in the office who thought they knew physics :-). Thanks again, F. Daly, Ireland
I ordered this on July 27 and received it on July 30th. That was fast shipping! From start to finish, it took about 1.5 hours. I used J-B Kwik Cold Weld to assemble it. The Coffee Cup engine ran the very first time! I would say that it is "highly recommended." William Rushing, Champaign, IL.
I thought it was great! My nieces and nephews love it. --Hugo Tress, Provo, UT
One hundred of our sophmore mechanical engineering students built MM-5 Stirling engine kits. The kits were great and the service was excellent. Building these kits was a very good learning experience for our students and we plan to do it again. --Professor Angela Moran, United States Naval Academy
Put together on Monday April 18 running every day on top of my aquarium light 9 hours a day every day replaced nothing great product highly recommended
You have quite a Kalashinikov of an engine. That is, I put it together with less than ideal adhesives, left out some parts, and the engine is still a straight shooter. A couple of guys here have worked on automotive Stirling projects and they were really tickled to see your engine running on a cup of hot water. Thanks very much.
I originally looked into Stirling Engines a number of months ago, and it ended up on my Christmas wishlist. I received the MM-5 for Christmas, and finished building it in about an hour on the 26th. I think I rushed a little bit too much, but I couldn't wait to get it together. In the process, I did bend the crankshaft a tiny bit, which causes the propeller to wobble a little as it rotates. My suggestion would be to attach the propeller and nut to the reducer prior to attaching them to the crankshaft itself. Since I had to screw the propeller onto the reducer, I applied too much pressure and that is how I bent the crankshaft (pulled down on it a bit, while attaching the prop). Other than that little mix up, the engine worked immediately on a warm cup of water and ran for a few minutes. When I ran it on a boiling cup, it ran for nearly an hour. A great gift for anyone who likes to see how things work, and especially if they are perfectionists. It is the perfect project for someone who wants to get it all exact, as the more exact you are, the better it is going to turn out. Now I hope to get the other models for my birthday.
Very easy to build, and the result is amazing. The engine can run on hot liquids or cold ice. It is amazing to see how fast this spins because it only runs on heat
Fun to assemble, fun to run, fun to understand. Thanks for developing the MM-5 kit. Horton A. Johnson, MD, New York, NY
I love it! The quality of the instructions and the quality of the parts are all very good! BTW, great product! Norwood Matt, Norwood-Near, Ohio
I ordered the MM-5 on 2/18 and received it on 2/28. Started assembling the evening of 2/28, worked on it on 2/29 and finished the morning of 3/1. After final assembly I attempted it's initial run on hot water; it ran just as I was expecting. I let it run for about 10 min. as I marveled at it and then tried it on Ice; ran on Ice too (which I think is incredible). After it's initial run I let it rest and then over the course of several hours ran it off and on with hot water; I timed it once and it ran for 35 min., haven't timed it on Ice as of yet. The LCD thermometer is a nice feature; lets you see how the "cold" side warms up as the engine runs (and I imagine cool down when using Ice). All the parts were in the kit as were easy to follow instructions; the on-line instructions were very helpful as there were additional assembly tips. I took the time to polish the brass parts as I wanted the engine to look as nice as possible. I am very impressed with this engine's simplicity, construction, appearance and performance and I'm eager to introduce others to this engine; this is the sort of machine that will trigger the creative genius in some people and I'm expecting to see that happen. This is an amazing little engine; I highly recommend the MM-5 Coffee Cup Engine Kit to anyone with an interest in energy use, production and conservation. And it really does run on Ice...incredible!