Sunnytech Sunnytech Hot Air Stirling Engine Single Flywheel Education Toy Electricity Power Generator M14-03-

I ordered one of these Stirling Engines when they showed up on the Gold Box deal, without knowing much about Stirling engines at all. It's been an enjoyable education. First off, the item arrived promptly and well-packaged, looking exactly as shown in the listing. It came with two of the glass tubes for the heating cylinder, the alcohol burner, two wicks, and an extra set of O-rings for the heating tube seal. It took longer to unwrap the glass tube than it did to attach it to the engine, and the machine was ready for use. I picked up a can of 95% Denatured Alcohol from Home Depot (available in the paint department) and fueled up the burner. My first attempt to run the engine was outside, revealing one potential issue with the design. Any bit of air movement tends to push the flame away from the heating tube, and will inhibit the engine from running properly. When I attempted it again indoors with the cooler and ceiling fans off, the flame stayed on the glass tube and the engine ran flawlessly. I did find that it will pick up a bit more speed if I hold the board down to the table, and not allow it to vibrate. Doing so puts all the engine force into turning the flywheel, and none of the energy is lost shaking the board. If you have problems with air currents when trying to run this engine, you can make a simple wind screen out of heavy aluminum foil. I cut a rectangle of foil slightly longer than twice the length of the heating tube side and wide enough that, when the foil is folder into a 'U' shape, it can go around the alcohol burner and heat tube, extending higher than the tube sits. I bent the two upper corners towards each other and stapled them to form a basic wind screen/chimney, and this keeps the flame concentrated on the heating tube. There's a nice video on Youtube explaining the concept of the Stirling Engine. This model is kind of between the Alpha configuration and the Beta. In the Beta shown in the video, the engine uses a single cylinder with a power piston and the scavenging piston. This model uses two cylinders, with one serving as the power cylinder and the other serving as the scavenging, but the principle remains the same. Considering the original Stirling design is nearly 200 years old now, it's pretty impressive that it's still one of the most efficient engine designs available. If you're looking for a fascinating toy with a certain nostalgic feel, or a terrific prop for a Steampunk display, or just looking for a spark of education, consider picking up a Stirling engine. They're fascinating devices. Youtube video on Stirling engine theory: https://www.youtube.com/watch?v=gQb2sN6UWkA

Very nicely made. Instructions are not fool proof!

This is a fantastic desk toy. The parts are, I believe, machined aluminum and it's built well. The only complaint I have with it is that the feet are smooth metal and so when the engine is at full tilt, the thing moves around on my desk and there were was some metal on metal squeaking. So I decided to fix it. To prevent the toy from moving around on my desk, I picked up rubber feet. Not only did it stop the engine from moving but it also stopped metal feet from rattling against my desk. Then to prevent the squeaking, I picked up some white model grease, greased the rods, and the flywheel surface where the linkages connect to the wheel, then promptly wiped up the excess. The engine runs beautifully now. Recommendation to the manufacture: please provide rubber feet and a small thing of grease in the package with instructions where to apply both. For customers: I ran the engine on 70% isopropyl alcohol and then with 99%. Both ran the engine perfectly but the 99% left a ton of soot while the 70% didn't. Your results may vary. Note: The video shown is prior to my fixes and it is also running on 70% isopropyl alcohol.

Amazing little gadget. The engine was well packed in bubble wrap and tape. Too much tape, but OK. There were instructions, written by someone whose third language was Klingon and maybe English was their fifth language. But they could be comprehended, and they really were not needed. The engine was completely assembled, except that (1) the glass hot cylinder was not installed. There is a spare. (2) the wick was not installed in the Alcohol lamp. I installed the wick (it helped to wet it with alcohol and rub it to a point) then put 70% isopropal alcohol into the bottle, lit it, and in under a minute. it was working. It ran for about 10 minutes and then ran out of alcohol. There was plenty of power to run the generator, and to shake the thing. That was the only issue with the thing, it vibrated enough to walk around and around. I had to hold it to keep it from walking on to the floor. I needed to check something, so I had to carry it. Walking around cooled the hot cylinder too much. Soon as I put it down it started running again. For the price I am completely satisfied with this item. I am amazed that the air can actually heat up and cool that quickly, but obviously it can. I am somewhat surprised at the power of the air heating and cooling. This is physics that you can touch. I hope my grandkids get it. The box contained: 1. The Engine assembled and mounted on the piece of wood. It was attached to the generator. 2. Spare O-rings. There were two spares, and the seal is 3 o-rings. 3. two glass hot cylinders, one is a spare. 4. The tiny alcohol lamp. Separate wick, Separate cork.

I have wanted one of these for a long time. I picked this one because of the price. There were not a lot of reviews, but it was similar to other models with plenty of good reviews, so i took a chance. Mine ran ok with normal 70% isopropyl alcohol. I went to walmart and bought the 91% and it ran a lot better. Then i screwed up, i put a few very small drops of oil on the moving parts. It would no longer run. I took it all apart and removed the oil and now its running like a champ again. I read somewhere to use pencil "lead" which is actually graphite. I imagine any dry lube would work. I have some molybdenum disulfide lube somewhere that I might try. The machining is good quality, the finish is good too. It came with a spare glass tube (looks like the bottom of a heat resistant test tube, like pyrex or kimex) but I cant be sure. It also came with an extra set of o'rings for the tube. About the only thing I didn't like was the base. It is a piece of wood, with a space for the burner and rubber feet on the bottom. No finish and the edges could use some sanding. The engine bolts to it and could be removed easily if you wanted to finish or replace the base. Dont leave the thing sitting there running. It vibrates quite a bit and it will walk right off the counter or table. Thats not a complaint or a comment about quality, just something I noticed. The little generator thing it cool, but unless its running at full speed, you will only see a dim red light. When it gets up to speed, you will see green, blue, and red. You can also remove the belt if you just want to watch it run fast. In all, I have had a lot of fun playing with it and experimenting. Try reversing the position of the cranks with an allen wrench. You can make it run backwards. Also, try icing the cold cylinder. Worth the money for sure. Arrived double boxed from China in perfect condition. I got it about 5 days after I ordered.