Wax Oven (Part 1)

[Gordhandas]

In a previous post (June 2023) I stated that I was going to build a wax oven using a donated mini-oven and a PID controller. Unfortunately life got in the way; until now.

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I have completed the oven and the PID controller to go with it.

The PID (Proportional - Integral -Derivative) controller will keep the temperature regulated at 2°C above the melting point of the wax.

The oven only works with a timer and that has been disabled. As has the top heating element.

The electronics have fitted into a junction box and it is held onto the oven by magnets. The temperature prove is connected with an aviation 2 pin plug.

Now the oven is working the PID controller needs to be "tuned" for optimal performance.

I also plan to use a baking tray filled with ceramic baking beans to act as a heat reservoir.

I also want to 3D print a part so that the temperature probe sits at the best place in the oven.

The easy bit is over the hard work now starts.

Wax oven with PID Controller

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Inside the PID Controller

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Magnets to attach to the oven

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Temperature probe

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Ceramic Baking Beads

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[Alan Smith]

I did a very similar conversion to a cheap supermarket mini-oven around 5 years ago. Still works a treat. I used a 100mm long K-type stainless thermocouple as a sensor. To locate it I just drilled a 7mm hole through the thin steel oven wall and used the M8 thread on the collar of the thermocouple to hold it in place. That put the TC as near the center of the oven as I could get it - not too near the top or the bottom- these things are notoriously position sensitive unless you have a fan in the oven.