I believe I'm suffering from irregular extrusions.
I have measured 50mm of filament from the top of the PTFE tube and marked it, then from Prepare > Move Axis > 1mm > Extruder I've increased the value of exactly 50mm and I ended up having 8mm left out of the PTFE tube. I repeated the test twice more, every time staring my measurement from the top of the PTFE tub: once I got 4mm and once I got 12mm... Weird enough they are all multiples of 4, even if 3 is not really a series...
If my understanding is correct this might either be caused by the extruder motor losing steps or by the gear slipping on the filament (so partially related to the variable filament section).
Question No. 1: is my understanding correct?
Question No. 2: is there any other obvious cause for this?
Question No. 3: how do I check if the extruder motor is losing steps? (I have a multimeter and a crappy oscilloscope)
Question No. 4: assuming the motor is working fine, what can I do to fix this?
Question No. 5: is it possible this is related to my other issue with the wobbly XY plane?
Thank you for your patience, I imagine this has been asked a hundred times already, but the search function of this forum doesn't seem to play nice with me...
EDIT
I run a few more tests and tried a different filament, with no joy. To exclude the spool unrolling from the equation I've cut a piece of filament, still extruded short of a few millimetres, not constant though.
Filaments I'm trying are all PLA, nozzle temp set at 200 and 220 during my tests... I can hear a very faint click every now and then coming from the hotend block, let's say 5/6 times on a 50mm extrusion...
Irregular extrusion lenght
Re: Irregular extrusion lenght
Do you hear clicking (slipping) noise when extruding?
Have you got your extruder size and temperature set correctly? (Factory nozzle is 0.3 mm)
I had similar issues with the extruder (clicking sound, skipping steps). First I increased the voltage (which sets the current limit) on the driver board, then I possibly overdid it... in the end I replaced both the stepper motor and the stepper driver (driver to DRV8825), which seemed more powerful, and it didn't cost much.
Have you got your extruder size and temperature set correctly? (Factory nozzle is 0.3 mm)
I had similar issues with the extruder (clicking sound, skipping steps). First I increased the voltage (which sets the current limit) on the driver board, then I possibly overdid it... in the end I replaced both the stepper motor and the stepper driver (driver to DRV8825), which seemed more powerful, and it didn't cost much.