MK2 PCB-Firmware setup

0 votes
asked Jun 26, 2014 in 3D Printer Maintenance by Dave52 (290 points)
edited Jul 3, 2014 by Dave52
hello friends
I am facing problem regarding my MK2 PCB heater. I am using an old thermistor with it as this heater has no thermistor attached. The thermistor model I am using is SD3. I have The present thermistor is of type 6.
One thing I have forgotten to state. This is a replaced heater.
I am giving you the approximate temperature. the bed becomes hot only at the temperature 60°C. but while using the older one the bed remained okay at 95°C. While printing, I fixed  the temperature for the new one at 45°C and continued for 3 hours at  a stretch.There, I had no problem. 
Now I am using maximum temperature 50°. Can you please tell me whether I have made any problem while I used the new thermistor?
For your convenience, I am giving you more specification here.
The PCB I am using is setup on the top of a copper platform which has VHB tape.  This gives around 1mm value value of authorisation between the PCB and the platform. This has a hole in the center by which the thermistor enters  the middle through that the thermistor enters and then it enters into the PCB hole where there is a glass sheet. ID did not permanently attach or epoxy PCB heater to the the thermistor, it is only in the hole.
Across the Thermistor, I am thinking of applying some thermal compound such as CPUs in order to pack the PCB hole .
Do you have idea please???

1 Answer

0 votes
answered Jun 28, 2014 by Arifin (1,390 points)
edited Jun 29, 2014 by Arifin

I had an IR thermometer that I utilized for measuring the temperature in different places across the printing surface.  On those areas, I used a few flat black stick-on dots for which the glass reflection did not affect the readings.

Then, I kept the bed to heat up for 10 minutes.  At that time, the thermistor recorded the temperature 65°C, after that I measured the the corners, central temperature, and a couple of spots. I found:

Rear left     =  79°

Center        =  88°
Rear Right  =  82°
Front Right =  84°

Front left    =  81°
Other         =  85°-89°

Therefore, the thermistor records appear to be off about 20°C.

the PCB bed take heat up to the required temperature in nearly 5 minutes, it is pretty nice. is a free printing support and help site for 2d and 3d printers. Ask and answer printing questions in Citrix printing, terminal server printing, 2d printing, 3d printing or any printing related problems and more. Register for free and earn points for questions, answers and posts. Printing help is always 100% free.