Nozzle temp osclillating 20 deg above 235 deg C
Hi Forum!
After month of more or less flawless printing I start to run into problems.
The temprature starts to oscillate after 235 deg. It oscillates between target temp and 260 deg.
F.e. 235,234 the immeadetly 260 then it drops after 2 to five seconds to 233 the 234, 235, 260,...
Please see att. pic. When setting the temp 10 deg. below this behaviour stops immeadetly.
I started to see this since yesterday, before the regulation worked great far above 240 degrees.
Please see att. pic
Prusa I3 Mk3 latest firmware
Cheers
Rubi
Re: Nozzle temp osclillating 20 deg above 235 deg C
Ive had that exact graph on octoprint happen twice.
Once was a bad firmware flash, reflashed firmware and it went away.
The first time thought, you arnt going to like this, was a partial break in the thermistor wiring, i had to completely disassemble my hotend to fix the break in the wire and reassemble.
Re: Nozzle temp osclillating 20 deg above 235 deg C
Hi Thank you for your input
My first guess was also a break in the thermistor wire, but that does not make sense.
The second i lower the temp while printing it goes away immeadetly and when I increase the temp it starts oscillating again immeadetly.
I think it might relate to the psu.
When you look at the graph, with the lower temp the bed temperature increases slightly.
I will try to log the 24V rail.
I don't think my firmware is corrupted because I had no problems since the latest firmware release.
On the other hand I already bought a new thermistor cartridge,...
Cheers
Rubi
Re: Nozzle temp osclillating 20 deg above 235 deg C
Hi
Problem was solved after Pid calibration. Now it holds the temp as steady again as I was used too.
I mixed up Pid calibration with Temp calibration which was of no help unfortunately, the naming of the Pinda probe temperature calibration menue is very misleading imho. .)
Cheers
Rubi