Minimum Z and E moves?
I am doing some research that requires very small z and e moves.
I assumed that the minimum z and e moves would be equal to the 1/(steps/mm), which I think is 400 for both the z and the extruder, meaning the minimum z or e move would be .0025 mm.
I think the printer is skipping moves such as
G91
G92 E0
G1 F15.
G1 Z0.0025 E0.0025
Is it possible that the printer has a minium value it will try to execute that is larger than 0.0025?
Have I made some other error in assumption or calculation?
Thanks for your help.
RE: Minimum Z and E moves?
My calculations for the MK4 show the Z minimum move is .02mm 8mm lead /400 stepper increments per revolution =.02mm per pulse.
XY use GT16, 16 tooth pulley with 2mm belts. 16x2=32mm per rev/400 = .08mm per pulse X and Y.
RE: Minimum Z and E moves?
Thanks, the information and your explanation were both helpful!
RE: Minimum Z and E moves?
actually, I think the pitch of the lead screw is 2mm, so minimum z-step is 5 microns.
RE: Minimum Z and E moves?
If it is a single start then pitch=lead. These are multi start lead screws, so pitch, or distance between threads does not equal Lead. Put a piece of tape on the lead screw. then move Z 8 mm. You will see the lead screw makes 1 revolution, or 8mm lead.
Same with the MK4S X, put a mark on the pulley, move 32mm and you will see it moved 1 revolution.
With Z moves stepped in increments of .02, why does the Prusa slicer default to some layer distances that are not evenly divisible by .02? Example MK4S with standard .04 nozzle uses a .15mm layer. That means the machine will move .14, .16, .14, .16 in Z for successive layers. That is a +-7% Z error in laying the bead. I am working on the Prusa Slicer enhancement request to add Minimum XYZ move definitions to the printers and to use them for layer distances and layer smoothing calculations.
I would like to see XY with .02mm minimum moves also, but that may be an MK5...