crown test different start/end locations

Community,

I realized drawing the crown that one of my thumb screw belt pulleys had come loose, I re-tightened all of them for each stepper. I still have a persistent issue with the gcode ending <> 1mm from the starting point for individual shapes. Even if things were slightly off square, I would think stepping forwards and backwards the same amount would put me in the same location.

Installing the stepper mounts, I did get a crunchy feeling in one of the motors, like something was getting ground up in there, that went away with a few rotations. I am still experiencing this issue in both axial directions.

My belts are tight but everything moves smoothly (everything is snug). The paper was taped very tightly to the build surface. fine tip pen homed and confirmed with slight pressure to the paper. I generated the crown gcode in estlecam as instructed and I created a generic sketch with hard dimensions in fusion 360 that was machined with a trace operation and an MPCNC post processor. It seems the larger dimensions are more accurate than the smaller ones in the areas of interest. This phenomena was replicated between jobs.

Maybe I need to start milling to worry about this tolerance, but I would have expected more dimensional precision from this test,

 

Please disregard!

I slowed my feed rate to about 10% of what it was (200mm /min or so). Saw much closer tolerances, the inaccuracy I am seeing now could easily be attributed to the pen mount and felt tip.

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