PID Controlled Ovens 

I undertook the complete overhaul of two donated, inoperable ovens with scrapped hardware and stripped electronics. Restoring these units was critical for our manufacturing capabilities as we needed drastically reduce propellant curing times and achieve the necessary glass transition temperatures for our high performance high temperature epoxies.

The process began with a complete teardown, removing all controllers, heating elements, and wiring, as the original systems were outdated and lacked essential safety features. The new design prioritized safety, preheating efficiency, and ease of operation. I used new PID controllers in conjunction with a Solid State Relay to precisely regulate the fans and heating elements. I completely redid all the wiring, installed new switches, and created wiring schematics that were taped to the side for future iterations/troubleshooting. 

The smaller yet trickier unit, our propellant oven, was considered unsatisfactory as the heating element was located on the floor with vent holes which caused the floor to reach extreme temperatures. Therefore, the new retrofit was a bit more extensive. The heating element was removed from the bottom and placed on top with a metal guard. To increase circulation throughout the oven, a cylindrical fan was used (originally for gas fireplaces!) with a duct. For safety, as propellant was being cured,  thermal fuses were also installed in case the PID controller failed and the heating elements were stuck on. A cork lining was also installed around all surfaces in case the underlying metal reached unsafe temperatures.

This redesign allowed for 6 4" propellant grains to be curing in the oven at once, drastically decreasing the curing time and increasing manufacturability within our lab.