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

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

The media could not be loaded. 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.

Very good for learning, its also fun to watch running. Though out of the box I'd recommend either greasing up or oiling the rods up because they like to bind sometimes.

This product feels sturdy and well made. It works as expected. The only issue is the engine runs smoothly, but it moves around on my desk. I ordered some rubber feet to put on the metal feet of the engine. This corrected the issue.

The media could not be loaded. This model Stirling engine is a low cost counterpart to the Boehm Stirling-Technik - HB7-AL2 which retails for ~$250. The Boehm is definitely a notch up in intricacy and quality, but for demonstration purposes, little is lost in the cost-cutting shortcuts that allow this model to be sold for $66. The wood base is cheap, naked soft pine, so I put a coat of polyurethane on it to toughen it up, but otherwise everything is stock that you see in the videos. The alcohol lamp should be run on ethyl alcohol (95% denatured from Home Depot's paint department). It requires a bit of warming up, and the hot side cylinder should be positioned for maximum cylinder volume when first heating. After a minute of heating, spin the flywheel, and the engine will run until the alcohol runs out (about 3 minutes). I like the clear cylinder head (half of a test tube) since you can see the cylinder moving. The LED does light up red, but it is pretty dim and transient; I think the small motor/generator puts a significant load on the Stirling engine since the scale is so small.I have found that these run faster and faster as they break in, and the red LED becomes more prominent. I noticed one reviewer tried to lubricate the engine, with poor results. Just run it for awhile and the parts loosen up.All told, for ~$66 it's a great toy. I also bought Sunnytech® Low Temperature Stirling Engine Motor Steam Heat Education Model Toy Kits Lt001 which works extremely well as well. I'm intrigued enough to think about the Sunnytech® Hot Air Stirling Engine Motor Generator Education Toy Kits Electricity M16-v4-d which uses 4 of these ganged together to run a small generator. It seems with the more expensive Sunnytech engines, they give you a better painted wood base.The product shipped from Shanghai which was a bit of a concern. But it was packed very well, and even though the delivery time was stated as 5-20 days, it actually arrived in 6 days.