Help configuring termistors

aidar

Hi. You should read this https://duet3d.dozuki.com/Wiki/Tuning_the_heater_temperature_control

peirof

@aidar mmm... O think that these info, its usefull after o have ajusted thermistors... If Duet dont read the correct temperature... The autotunig its not usefull....

Think

EasyTarget

@peirof
For fine tuning the thermistors the process you describe seems correct.

Start with a approximately good setting; I just took the manufacturers rating, but one can look for examples online, or directly measure it as you did.
Heat up until it stabilises; read the temp with a known good thermometer (I have a cooking thermometer one for this, I'm not actually sure of the 'good' part)
Refine the settings (by educated guesswork based on the results), reboot, reheat and repeat until you get to the accuracy you want.

~~I dont think there is any better method outside of proper lab with the appropriate test chambers etc.~~ edit: I'm wrong; see below.

At some point you have to decide your setup is 'accurate enough' and just get on with printing. In my experience there is no need to have uber-accuracy.

dc42

Go to the RRF online configurator thermistors page, select custom thermistor. There you can enter 3 resistance vs temperature values.

Veti

the ones from the vulcano look like a B3950
https://www.makeralot.com/download/Reprap-Hotend-Thermistor-NTC-3950-100K.pdf

the normal ones appear to be a semitec 104-gt2
https://www.mouser.de/datasheet/2/362/P18-NT-Thermistor-1535133.pdf (104NT-4 is a replacement thats suppose to have the same characteristics)

peirof

@dc42 in Heaters page? I cant see how put three resistance value... Ask for resistance at 25,B and C

nhof

peirof

Hi.

What its the fórmula, that transform measured resistente in to temperature...?

I cant adjust temperature control... I hace try a lot of valours, and i d like see the fórmula, for know how affects variables

dc42

@peirof, look up Steinhart-Hart thermistor model.

peirof

@dc42

This Web... Can be used with Duet?

Thermistor model