I made a little progress on the hot plates. Mostly just a lot of little things. I soldered some of the wires, added some ring terminals for the relay, changed the wires on the front switch, added a green grounding wire for the aluminum plate and soldered on some header pins so I can plug in to the Arduino.

I also hot glued the ac / dc converter in place. I am not a big of hot glue actually. I guess I am just used to doing things the industrial way. But since I already gutted the usb charger for this part, I decided to go with it. I hot glued it to the side of the solid state relay because I didn't want to glue it to the case. The relay is screwed in and can be removed fairly easily. This way if I do need to pull it off or change it I can. I is actually sturdier than I thought it would be and still looks fairly clean. Maybe this stuff is not so bad. I also put a few dobs of glue around the wires I soldered on to act as a bend relief. All in all, not bad.

My aluminum plates are in the mail but wont get here until Jan. 13th and the thermisters wont arrive until Feb 11th. So I looked around the shop for a scrap piece of aluminum I could use to test with. I found this which is a little smaller than I need, but should do the trick to test.