I used the following parts:
- Tempco 500W 120V heater
- generic 100K thermistor
- 24VDC fan - FCI DA-119B-W24 with ball bearings
- Crouzet GN84137180 250A 660VAC SSR - ridiculous overkill, but handy at the time
- Anderson power pole connectors
- lugs and wire
- 1" square aluminum tube
- a couple printed parts to hold things in place with zip ties.
It's all working fine, but I need to finish a couple things. It needs a TCO to kill power in the event of an SSR or fan failure, and something to cover the electrical connections at the heater bar. I also need to figure out a way to protect against the controller losing its mind - maybe a low temperature TCO in the enclosure that will cut main power if the enclosure gets too warm.