TwoTrees Sapphire Plus SP-5 integrated PTC chamber heater

Replaces the rather useless metal plate that is covering the control board of the printer with a chamber heater.

Uses the readily available PTC heater modules; “220V AC 300W” in my case (more like 450W btw). 
The housing of the module needs to be slightly modified; remove the original mounting ears and flatten the exhaust part if you want to use the top cover.

The top is intended to be put together with a piece of metal mesh as seen on my photos. Helps to distribute the air and protects the printer and you.

I swapped the fan for a Sunon MF60252VX1000UA99 so I can easily PWM control it and use it on its own. Allows for cooling of the control board and chamber when the heater is not enabled. With the heater at full juice it works best with the fan at ~80%.

The fan sticks out about 9mm to make the whole thing as compact and leave as much Z height as possible. The mains power cables also stick out a bit. Check if you have mounted something to the control board that could interfere; By my measurements, everything should hover a few millimeters above the stepper drivers.

Main body allows for a thermal fuse to be placed right next to the heater; I have used a 74°C one but haven't verified yet if it's the right choice.
If you want to use this design, USE A FUSE! I will not be responsible if you start a fire!

I strongly recommend using quality ABS filament or some other type of filament that can handle the high temperatures.
I measured the exhaust air to be up to 150°C.
Please do not run this setup unattended before you have properly confirmed the function.