DjuiinoStar Most Classical Low Temperature Stirling Engine, Unique Coffee Timer, Best Gift Option, Educational Toy, Steam Engine Model DLTD-303

This is a terrific gift/contraption/geek toy/objet d'art AND objet de science! I had been wanting a good, relatively inexpensive, low-temp Stirling engine for some time, and, while this isn't low-temp enough to run solely on the heat of the palm of your hand (as some are, or at least *claim* to be), it's perfect as a temperature indicator for hot coffee and the like. It's a great value, well-made, easy to assemble, aesthetically somewhere between steam-punk-chic and a more Art Deco/Bauhaus, chrome-tinged, industrial design, and it works very well! I haven't tried yet any sort of lubrication of the moving parts, so I'm probably not getting maximal operation out of it, time-wise, but I find its gentle squeak endearing, like a tiny component from Chitty Chitty Bang Bang's inner workings. Besides, it runs for quite a few minutes before it slows down enough to let me know my coffee is no longer too hot to drink. If you or a loved one is a fan of science-based gizmos and toys (I hesitate to use that word, because this is so much more than a toy), you will get great satisfaction and pleasure out of this device. Arrived quickly and well-packaged, so no complaints there, either. Five stars!

I could probably go on praising this machine and the company that stands behind it for hours. And the machine can and does carry on for hours, pleasantly ticking away atop a mug of tea. But I'll keep it to the pertinent details so you can get on with ordering yourself one and enjoying it as I'm currently enjoying mine. Not only is this machine a work of art, beautifully crafted to show off it's mechanism, it's also a very effective functional demonstration of a centuries old technology. And a fantastic example of a handful of scientific principles. Not to mention a stunning and entrancing conversation piece that's guaranteed to amuse just about anyone. Firstly, the packaging these machines are shipped in is very sturdy. They really care about it getting to you in perfect shape. Second, the machines themselves are very well made. They don't seem to have spared any expense in quality or craftsmanship. Third, and most important, this company really stands behind their product. Customer service correspondence is prompt, attentive, and eager to please. Sure, these engines are really just very elaborate toys. But I have no doubt that mine will last, and continue to bring joy and amusement, for a lifetime. The perfect gift for that person who's hard to shop for. The perfect addition to anyone's collection of curiosities. It's just as much at home on a desk, a mantle, a window sill, or your coffee table. Fair warning: you're going to want to collect more of these engines once you get this one out of the box!

Very nice! Had to push hard to get the connecting rod to snap onto the shaft, but then smooth sailing. Works nicely. Cranks away for many minutes over a steaming mug.

Unless this device is perfectly adjusted the flywheel will rub against the plastic exhaust tube. It is easy for an adult to assemble but children will need help with assembly. (Once it is put together it no longer fits in its box.) It took me a few minutes to assemble it, just a bit longer than it took me to reheat a cup of coffee in the microwave oven. Once the device is set onto the hot coffee cup it will turn, making that weird scraping sound, until the coffee cools.

Well two weeks to Xmas I just opened and tested various gifts and several had flaws, so I was very soothed to get to this one and find it is perfectly flawless and seems sturdy enough that assembling, testing, disassembling and reboxing seemed to hold zero risk of anything bending or breaking (unlike so much annoying cheap plastic junk). It is just so nice to see a sturdy, meticulously crafted toy in this era of disposability. And yet, with quality so high, the price is great too! Amazing! I love this because it is a beautifully simple example of concepts that have changed the world. With this you can open a discussion and explain to a kid all sorts of amazing stuff from generators and mills to trains and cars. Experiments can be dreamt up, such as putting various materials between mug and device to compare heat transfer, or trying it outside in the winter cold, using tepid water, to test if it needs heat-heat or just relative heat. Plus it's just plain fun and looks lovely. My only complaint would be that they don't include the graphite lube (and you want that lube! thing squeaks infuriatingly when operated without!). I suppose they don't want the fuss of including a little tube or stick and then handling complaints when it gets squished and makes a mess, I dunno. Or maybe everyone but me already has graphite around the house. It is very useful for applications where oil lube would gunk up with dust. Anyway, definitely add some to your cart with this engine. I found this nice small cheap tube: https://www.amazon.com/gp/aw/d/B07KBT3PDS/ref=cm_cr_arp_mb_bdcrb_top?ie=UTF8

High-quality, responds to tweaking, needs to be clean, mesmerizing and delightful to watch

I am a high-school physics teacher, and bought this to demonstrate how a heat engine can perform work. It was pretty easy to set up if you read the directions, and it seems pretty sturdy (obviously it is still a delicate instrument and care must be taken if you let students or children handle it. The unit is very attractive, and the clear cylinder allows the students to see what is going on with the displacer and work piston. Having a separate work piston definitely helps students see that the displacer is just moving air, not doing the work. When it begins to slow down on a cup of hot water, adding ice to the top helped the students see that it is the temperature differential that matters. Then one of my students asked if it would run backwards if we put ice on the bottom! Put some ice cubes on a towel (both for insulation and to reduce the mess), give a bit of time to establish the temperature difference, then give it a gentle nudge and it runs in the opposite direction from before. Leading from this demonstration, I asked my students if they would like to do a bit of mechanical engineering and build their own Stirling engine, and they excitedly said yes! I've got six teams now working on different designs. It will be interesting to see the results, but this demonstration aid definitely got them "rev'd up! For AP Physics students, this is a great entry into the laws of Thermodynamics. I've paired it up with a "Thirsty Bird" which illustrates a heat engine based on thermal expansion.

It is very easy to assemble and comes with tips on how best to keep the engine running as well as possible. It functions very well right out of the box, and goes faster the greater a heat differential you manage to create between its surfaces. I wouldn't try anything much hotter than boiling water, but it's a sturdy little workhorse that I've seen run for about an hour sitting on a mug of boiling water. TIPS: To make run for longer, place it on top of a thermally insulated container, like a thermos or thick mug, full of boiling water. When the water cools down, you can put something refrigerated on the top surface to get another ten minutes out of it. To make it run faster, place something very hot beneath it and very cold above it simultaneously. It's probably best not to do anything too extreme (although they're cheap to replace if you break it), but something like a mug of boiling water and some frozen gummy bears or coins kept in the freezer should be ideal. Ice is an option, but it will melt and make a mess. The instructions recommend graphite as a lubricant, but I didn't think I could get it fine enough to not be detrimental. I just put a little bit of oil on the places where there's metal on metal contacts. Lubrication should make it last longer and run faster.

Gives me something watch , the simple motion