Another simple and inexpensive kit that works well as a team project is the Exploring Kid Steam Engine Kit, which also retails for $29.99. This mostly plastic kit, when assembled, includes a ...

The $29.99 all-metal desktop Stirling engine kit is one of the simplest. It can be assembled in 15 minutes and is recommended for ages 14 and up. Also for $29.99 is the Exploring Kid Steam Engine Kit.

Try this same build using PLA for the hot parts, and you’ll quickly end up with a pile of molten goo. To make such an engine work, valves are required to allow steam to flow into alternating ...