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.

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