SunnytechMini Hot Air Stirling Engine Motor Model Educational Toy Kits Electricity HA001

This thing is amazing! First off, it came packaged in 3 boxes. A fairly large box with air packets for cushioning, then there was a smaller box with yet a third smaller box within it! I did notice all Oriental (Chinese per chance?) writing on all of the boxes, but the very small engine was found intact. I was a little concerned by the negative reviews I've read, but I am very pleased with the quality control on this item. There was also a slip of paper written in English with simple instructions inside the box.All the screws were in place, all the rods, linkages were intact, everything was tight and looked ready to go....... and (being a 62 yr. old kid) I simply had to fire it up immediately! I poured a little alcohol in the alcohol lamp, threaded the wick, placed it in position and lit it up. Within half a minute (the directions say 20 secs.) I gave the flywheel a spin and it took off like a champ. If you leave the flame in direct contact with the motor, it keeps gaining RPM until it could vibrate off of the table. I merely moved the lamp away a wee bit and it slowed down to a manageable speed.I, too had a problem with the magnet falling off of the alcohol lamp, so I put a drop of Gorilla glue on it and set the lamp on top and it is quite solid there this morning.I had some trouble with the wick working down inside of the lamp due to vibration. As the wick is made of several strands of string, I thought I could tie a simple knot in it to hold it in place. If I failed, I figured I could replace the string. This simple knot seems to work pretty good as the wick now stays in position better. It did shorten the wick somewhat, but it still seems to work pretty good. I can always replace it with a longer wick.I couldn't help myself, but I ran two full tanks of alcohol through the lamp just watching this thing run. It seems impossible that it could operate, yet it does!Back to the review...... It came with a small foam wrap that had two glass bulbs and two O-rings in it, When I first opened the third box, a very small nut fell onto the table. I couldn't find where one was missing on the engine, so I simply double-nutted it on one of the screws to keep it from getting lost. I assumed that it is also a spare part? Tighten with care as this is a very small nut/screw.The base measures 1-7/8" by 4" and the engine stands about 2" tall overall.It appears to be built pretty good for a toy, the fit and finish being very good on the machined parts. It has only one flywheel (the catalogue description claims "twin flywheels". The base is either stainless or nickel plated steel. The Stamped parts are well made of fairly thick steel (again, these too look stainless) with a brass 1/4" elbow for an engine housing! It looks to have glass cylinders with a metal piston on the hot (top) side and a plastic piston/cylinder on the cold side of the engine. The connecting rods have ingenious linkages to the crankshaft with keepers to hold them in place. The unit came fully assembled, all nuts/screws were tight, and the unit is pleasing to the eye. It seems that Sunny Tech got their quality control straightened out.To me, this is an amazing work of science at a very affordable price. I highly recommend it to anyone with a mechanical aptitude.-------> I'll be quiet now. ;-)

When I saw this item, I was excited by the photos and low price. I've always been fascinated by these "hobby grade" model engines including the Jensen Steam Engines. I received the engine quickly and packaged in a double box (nesting doll arrangement) that was very secure and insured the item was 100% undamaged during shipping. I connected the main piston connecting rod by simple finger pressure, filled the bottle with 90% alcohol, lit it and waited about 30 seconds before giving the flywheel a spin. Instantly, the engine began to spin, slowly at first, then accelerated gradually to quite a high RPM! In fact, the RPM was beginning to be so high that I blew the flame out to adjust the wick lower in the bottle. Re-lit and restarted and the RPM's were slower and seemed to be just fast enough to prevent over-speed or damage to the detailed mechanism. My 14 year old son was instantly amazed at it's performance and was very curious about how it worked. This little engine provided a father-son moment that will never be forgotten. I provided the physics explanation of how it worked and the differences between internal combustion engines vs. external combustion engine (which this is). We played with the engine for at least an hour, experimenting with different wick settings, fuel bottle position (which affects RPM's) and fuel types (190 proof grain alcohol). Overall, I am MORE than satisfied with everything this engine represents. The engine also came with a spare main piston bulb should the one installed break or crack and a spare fuel bottle. I have fired up this engine every day since it arrived and it seems only to run better and faster each time! I'm not sure why other owners have posted negative reviews of this engine and can only speculate they might have done so because they lack the knowledge of basic mechanics or physics and have little experience with "hobby grade" models. I have years of experience with R/C models (including a $5000.00+ Traxxas T-Maxx with an OS .30RG upgrade) and planes, trains and cars. If you understand the hobby type models and are willing to accept the fact that mechanical things can and do break, then this model engine will satisfy your curiosity and stand as an extremely well made addition to your collection. I wouldn't hesitate to buy another engine today! Honestly, I am extremely impressed with this engine and the manufacturers!