Open flames are not permitted at the Champlain Maker Fair, and commercial hot plates are difficult to control and unnecessarily large. And I did not make them. So….

I took a page from my friend Ralph Lemnah’s book and purchased some PID temperature controllers off of Amazon. Cut out some slaps of ¼” aluminum plate from scrap I had lying around, mounted the thermistors and heating elements under the plates, made feet out of ceramic insulators (thanks Ralph!), and printed the cases using my 3D printers.

The hot plate (with insulator feet) is on the left; the temperature controller is on the left.

The PID temperature controller is in the middle, with the heat indicator LED above it. The solid state relay is to the left, fuse at the back right.

Controller working…