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.

Model steam ... engine models up for sale at garage sales and various internet auction sites. The problem with these engines is the fact that many of them were sold as rough casting kits.

Model steam ... engine models up for sale at garage sales and various internet auction sites. The problem with these engines is the fact that many of them were sold as rough casting kits.