@DigiD Yep, this worked great! I just iterated over it a couple times and now temps are right where they should be when printing. Thanks!

@DigiD this is a good tip I think. I've already got all the data, since I measured the temp across a variety of set points with a k type thermocouple dipped in thermal paste (thats where I got the data for the graph).

@Veti I actually used the 25/100 value for B, which, sure, is far below printing temp, but is also pretty standard practice I think? At least from the web hunting i did this morning. I dont really have any way to accurately get the thermistor to high temperatures and measure its resistance.

also, I wouldnt call that large a deviation "accurate." Its 10% off at 100 degrees, if we interpolate.

Hey all, i'm reviving an old printer with a Duet2 board. A few years ago I tried to upgrade the board and struggled to find calibration files that would work. Eventually I got back around to it, and everything seems to be generally working properly now except for hotend temperature.

Its an old jhead with the original 100k thermistor (5 years old now, wow!). Digging around in the old Marlin firmware I had on the old ramps board, it looks like its a standard EPCOS 100K Thermistor, and i've set the values in the config file accordingly:

M305 P0 T100000 4092 R4700

i'm getting an interesting linear temperature deviation (measured with a thermocouple in some thermal paste around the nozel) and wondering how to correct for this:

I'm wondering what this error might be indicative of. I think the setting for beta is correct, but dont really know where to start changing H and L. If anyone has anything to offer here, looking forward to hear about it!