Layer misalignment with certain filament
I'm having what seems to be layer misalignment, but only with certain spools of PLA filament. When it occurs with a particular filament it seems to occur at the same locations for the model. So that makes me think it's not filament inconsistency since then I would think it would happen randomly throughout a model. Here's a comparison of badly performing filament (the blue) against a good one (the grey), which makes me think it's not mechanical since I would think that would affect prints no matter the filament:
And here's the badly performing one used for a 3DBenchy print:
Any ideas of what I should try to tweak?
Re: Layer misalignment with certain filament
I just gave up with this teal 3DSolutech filament and returned it. Nothing I did made any difference. However the exercise did teach me about tuning the extruder and extrusion multiplier, so it was a useful exercise.
RE: Layer misalignment with certain filament
It looks like a loose belt, even a loose gear not properly assembled.
Check your set screws on the drive gears.
Flat First: Drive gears must be tightened flat-first.
1) Start with both set screws fully loosened so the pulley is free to spin on the motor shaft.
2) Align one set screw dead center with the flat on the motor shaft, slowly tighten the screw until it fully contacts the flat surface.
3) Torque the flat set screw to spec.
4) Now tighten the jam set screw, and torque it to spec.
Once tightened, never touch the flat set screw unless the jam screw is first fully loosened.
Why Flat First? Set screws have flat ends. If you tighten the jam screw first the set screw on the shaft flat doesn't fully contact the shaft, only one small edge of the screw surface is biting. Reversing torques can easily shift the shaft to a position the flat screw no longer contacts the shaft. This lets the jam screw wriggle loose. And after a while, vibration loosens the screws until the gear is free to rotate.