Hotend Thermistor Calibration
Hi all!
I tried to print some Iglidur I150 for the first time and did some calibration prints for testing purpose.
They recommend a hotend temperature of 250°C and i used that for a 25 mm cube (Vase mode).
It came out quite ok but the surface of the walls is not what i would call excellent....It was late yesterday so i stopped my tests.
I will do some heattowerds tonight to see how it behaves. It seems to me that i printed a bit too cold...we will see.
But that is just the story around my question. In short:
If my MK2S is at room temperature i can read a value of 32-33°C on the display (for both hotend and bed, they are always quite the same when cooled down). My room temperature is by far cooler. Something in the 19-23°C range. That would mean that at least at room temperature my Thermistor is off by around 10°C.
What temperature is your display showing when your printer is cooled down completely?
And if i am off 10°C at low temp does that mean it is off by 10°C at printing temperature too?
I know that there is a table in the firmware which is supposed to compensate/calibrate the thermistor, but what if the "mean variation" (i mean how much an thermistor s values can be off) is just too big?
Wouldn t that mean that i m off with all the temperatures for all materials?
Of course i a doing material tests for all new materials/filaments but that would just underline one more time how important it is.
What is your opinion in that matter?
Thanks for input and have a nice day.
Greetings
Mathias
Re: Hotend Thermistor Calibration
The thermistor used in the extruder is not very accurate at room temperatures, but become more accurate at higher temps.
I don't know the specs of this particular thermistor, but some variability should be expected (and the thermal resistance from the nozzle to the thermistor (through the heat block and the nozzle to heat block interface and the thermistor to heat block interface) also has some variability.) The location (drafts and room temp) will also affect.
For materials like PLA which have a side temperature range of operation you should have no issues. For materials with tighter tolerances, it is worth testing that material with small test items at different temperatures. Time consuming but worth it if you need top performance from sensitive materials.
Any advices given are offered in good faith. It is your responsibility to ensure that by following my advice you do not suffer or cause injury, damage or loss. If you solve your problem, please post the solution…