Heatbed thermistor

I was planning to get a silicone pad heater and machined aluminium plate but I could not find a nice plate with decent price. So I had to go with a traditional PCB with glass plate. I ordered PCB Heatbed MK2B and a bunch of NTC 3950 thermistors. I will use the rest of the thermistors with my environment control unit.

The power wires were easy to solder but I might have bought a bit too heavy wire for it. I use 4 sq mm wire between RAMPS and heatbed. That is pretty much the thickest fitting in the RAMPS screw terminals but it isn't very flexible and might cause me headaches when I try to clean up the wiring mess.

Most of the instructions use Kapton tape to attach thermistor to the heatbed. Unfortunately, I have none here so I had to improvise. I soldered the thermistor to a longer wire with heatshrink and thermal protective sleeve. Then I placed the thermistor in the PCB with some heat resistant grease as I did not have any thermal paste either. I secured the wire in place with some masking tape and then I added good amount of bathroom silicone on the wires. According to the label the silicone is good till +180 C degrees.

Not very pretty but seems to hold pretty well. I hooked up the wires to RAMPS and heated the bed up to 95 C degrees and everything worked ok. In any case this part is hidden so the appearance does not really matter.