Extruder hot end heating problem
A couple of days ago I started having problems with inconsistent extrusion. I started the normal cleaning the hobb gear, adjusting the tension and such. The extrusion stayed inconsistent. I use normal PLA at 210-215 / 65 and the gear would either slip on the filament , chew through it or the stepper would miss steps. I thought it might be a partial clog and increased the temp to 255 and manually extruded and got a nice even flow. When I set the temp back down to 210 it binds up again.
Today I noticed that while the printer is sitting idle it has a large mismatch in resting temps. The bed is reading 28C and the Hotend is reading 38-40C at a complete idle sitting turned off for several hours. I borrowed one of those laser thermometers and it reads the idle temps on the bed at 21C and the heatblock as roughly the same which are in agreement with my digital room thermometer. The LCD still says bed:28 and hotend:38.
When I set the temps to 210 and 55 I get Bed temps of 46-50C and one cold spot in the front/center/left at 33 and hotend temps unfortunately are beyond the range of the thermometer. At anything less than a setting of 255 the extruder cannot push the filament (I tried 5 different rolls). It skips even when manually assisted with some pliers. There is some flow but the stepper cannot push through.
Is there a way to re-calibrate the temperature of the heat block?
Re: Extruder hot end heating problem
There is no way to re-calibrate the temperatures other than to install a new thermistor.
You problem is most likely to be a work nozzle and/or PTFE tubing. If I was having your problems, I would replace the nozzle and check/replace the PTFE.
Peter
Please note: I do not have any affiliation with Prusa Research. Any advices given are offered in good faith. It is your responsibility to ensure that by following my advice you do not suffer or cause injury, damage…
Re: Extruder hot end heating problem
Thanks Peter, I am going to try that as I have those parts on hand. I did find that I had a loose set screw on the sensor cartridge. Snugging it back up didn't seem to do much. This head had a fan failure overheat several months ago and has been a bit irregular since, so a part failure wouldn't surprise me. I'm trying to find a US supplier for replacement parts and not having much luck.
Re: Extruder hot end heating problem
E3D US Reseller: https://www.filastruder.com/
The grub screw holding the thermistor can be loose-ish. Tighten it too much and the cartridge will collapse.
Peter
Please note: I do not have any affiliation with Prusa Research. Any advices given are offered in good faith. It is your responsibility to ensure that by following my advice you do not suffer or cause injury, damage…