The oven of my quartz crystal oscillator

I decided to include not only the crystal, but the whole oscillator circuit inside the oven.
This will have some size, so I selected as the oven enclosure, a double wall, vacuum insulated coffee mug.
I 3D printed a forming piece and I formed a heating mantle by winding 3 layers of 0.12 mm copper foil.
Unfortunately PLA cannot withstand the oven operating temperature (up to 70 C), bakelite is cut for the top and bottom of the mantle.
Two resistors of 47 Ω 7 W and a sensing thermistor complete the mantle.
In order to design a suitable controller, a model of the thermal behavior of the oven is required.
To generate and collect data, 12 V DC is applied to the heater resistors and the resistance of the thermistor is monitored. Power is cut when the thermistor resistance drops below 2 KΩ, but the recording of the resistance continues for another 8 minutes.
After several tries, I concluded that the simplest, acceptably accurate model would consist of three thermal capacitances and three thermal resistances.
Let it be clear that the model is useful for designing the controller, but does not necessarily the physical operation of the oven.
In my next video, I will describe the oven controller.