Thermistor Offset Question

tsitalon1 · 2 Aug 2021, 05:54

Hey guys, recently swapped to Phateus Dragon hotend and slice heater cartridge, but still using the same thermistor.

It "feels" like I'm about 20deg cooler at 200c than normal, but I have no solid way to confirm.

I want to add a 20deg offset and see what happens, what's the best way to do that on a Duet 2 WiFi running on 3.2.2 ?

Current thermistor config is:

M308 S1 P"e0_temp" Y"thermistor" T100000 B4725 C7.06e-8 R4700

tsitalon1 · 8 Jan 2021, 23:51

So I picked up a good certified DVM and using a k-style thermocouple, I was able to measure 185c when the printer believes it's at 200c That's a fairly large delta.

Any way to compensate?

Phaedrux · 2 Aug 2021, 05:54

@tsitalon1 said in Thermistor Offset Question:

I want to add a 20deg offset and see what happens

M104 S200+20

jens55 · 2 Aug 2021, 06:05

@phaedrux said in Thermistor Offset Question:

@tsitalon1 said in Thermistor Offset Question:

I want to add a 20deg offset and see what happens

M104 S200+20

I think the op is looking for a way to correct the displayed temperature. IE, currently the printer says the hot end is 200C when in fact it's only 185C. Op wants the printer to say the temp is 185C

Phaedrux · 2 Aug 2021, 06:13

@jens55 You're right! I need to go to bed.

@tsitalon1 said in Thermistor Offset Question:

still using the same thermistor.

What thermistor is that exactly?

@tsitalon1 said in Thermistor Offset Question:

T100000 B4725 C7.06e-8 R4700

This would be correct for an E3D thermistor. Is that what you're actually using?

tsitalon1 · 2 Aug 2021, 12:39

I won't pretend that I made this change the "right way", but changing the M308 line to the below resulted in my displayed hotend temp to match the Type-K probe I inserted into the heater block

M308 S1 P"e0_temp" Y"thermistor" T100000 B4815 C7.06e-8 R4700

yes, I am using a E3d themistor, not sure why i needed to make this change, but I have verified printing looks normal now.