I am in the process of buttoning up a Nitehawk conversion on my Voron. I also replaced my extruder thermistor with an OE replacement purchased from a reputable vendor.
Post setup, my heated bed is reading spot on (it's 18.3 C in my basement aka 65 F). I verified that my extruder is also at ambient temperature by wedging a Thermapen under its silicone sock and letting it acclimate for 10 minutes. The I'm not sure why the extruder would be reading high.
I bought a spare thermistor and wired it in. The result was identical.
Thoughts? Ideas? I'm pretty sure I have the Nitehawk and thermistor set up correctly.
[extruder]
step_pin: nhk:gpio23
dir_pin: nhk:gpio24
enable_pin: !nhk:gpio25
heater_pin: nhk:gpio9
sensor_pin: nhk:gpio29
pullup_resistor: 2200
sensor_type: ATC Semitec 104NT-4-R025H42G`
My voron with can toolhead, using a pt1000, I'd accept +/- a degree or so but that's a bit more than that. Could trying calibrating the pullup value manually? I'm using Generic 3950 for the sensor types on the Semitec 100k thermistors (chamber temp and plate temp are both using one of those), had the best results with that personally, could see if that helps things.
Agree that this seems like a bigger than desired difference.
Thanks for the point of reference. I am going to be doing some measuring and math tonight to try to figure out where the source of error is and how much it might/not matter when hot.
Before nitehawk I was using the same hot end and I copied the thermistor type from my prior config while setting up. The bed and extruder were much closer to each other when cold then.