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 ...

First, we’ll start with the DIY version that you’ll put together yourself and give you a list of items you might want to include in your care kits. Then, we’ll list some of our favorite care ...