Full Steps on X&Y axises
I've started designing and printing jewelry on my i3 MK2S and noticed some banding while using E3D's experimental 0.15mm nozzle (the nozzle is amazing btw). I'm getting artifacts that look like the artifacts you get on delta printers using 1.8-degree motors and 8-bit boards. I'm wondering if anyone has looked into simple modifications to the X & Y axis so they can use full steps exclusively and move 10-20 microns per full step? Would I need to swap out the motors for 0.9-degree motors, use belts with more teeth, and/or add gears to the motors?
Re: Full Steps on X&Y axises
Currently the XY steppers use 100 (1/16) microsteps to move 1mm, 10 microns per microstep.
Using full steps that would be 160 microns per step and with 0.9 degree steppers, 80 microns per full step and 5 microns per microstep.
Using 0.9 degree motors would halve the maximum speed of the XY axes, but the 1.8 degree steppers using microstepping currently fall into your requirements.
However, with a 0.15mm nozzle and layer height of (say) 100 microns, the problem is with your extruder stepper. It takes around 161 microsteps to feed 2.4 mm^3 of filament. That means only 1 microstep will be generated for every 1mm of line drawn, which is barely sufficient to produce an even line. The pressure variation in the nozzle will help, but you will need to print at a minimum of 50mm/s and that may net be possible due to acceleration.
If you were to swap the E motor for a 0.9 degree stepper, I think that would help.
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…