{"product_id":"low-temperature-stirling-engine","title":"Low-temperature Stirling engine, runs on a cup of hot water","description":"\u003cp\u003e\u003cstrong\u003eStand it on a mug of hot water and give the flywheel a flick. It keeps turning for as long as the water stays warmer than the air.\u003c\/strong\u003e\u003c\/p\u003e\u003cp\u003eNo fuel, no batteries, no switch. A Stirling engine runs on a difference in temperature, and this one is built to need very little of it: the big flat chamber takes heat from the mug underneath and loses it through the top plate, and that difference is what drives the piston and the flywheel.\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eHow to start it:\u003c\/strong\u003e set it on a cup of freshly boiled water, wait a minute for the base to warm, then spin the wheel by hand. If it stops, the water has cooled.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWhat it is made of,\u003c\/strong\u003e per the maker: mirror stainless steel base, glass cylinder, bearing-steel shaft on precision bearings, zinc alloy flywheel, gold finish. Runs dry, no oil.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eIn the box:\u003c\/strong\u003e the engine, assembled. Nothing else.\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eWho it is for\u003c\/h3\u003e\u003cp\u003eSomeone whose desk already has a caliper on it. It is a physics lesson you can leave running during a coffee break, and it is quiet enough to do that in an office.\u003c\/p\u003e\u003ch3\u003eWhat we have not checked\u003c\/h3\u003e\u003cp\u003eWe have not run one ourselves yet, so we are not quoting a speed or how long it keeps going on one mug. The maker gives no dimensions beyond the photos. It is a model, not a toy for small children: the glass cylinder is thin.\u003c\/p\u003e\u003ch3\u003eDelivery\u003c\/h3\u003e\u003cp\u003eFree and tracked, to the United States, Australia, New Zealand and Canada alike. \u003cstrong\u003eOne to two weeks.\u003c\/strong\u003e We hold no stock and we have no warehouse of our own: the order is picked and posted by the supplier after you place it, which is why we give a range and not a date.\u003c\/p\u003e\u003cp\u003e30-day returns from the day it arrives. Return postage is yours, the price of the item comes back in full.\u003c\/p\u003e","brand":"ARVONELLE","offers":[{"title":"Gold","offer_id":50499919085759,"sku":"14:350850#Gold;200007763:201336100","price":44.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0760\/5826\/3743\/files\/S884d94c8e0094fadaea1dc12024cbc35W.webp?v=1790306040","url":"https:\/\/arvonelle.com\/products\/low-temperature-stirling-engine","provider":"ARVONELLE","version":"1.0","type":"link"}