On 12/11/2015 2:03 PM, J. wrote: > First hunch: > Sloppyness in the z movement or in the spindle bearings. With lost steps as a > result. > > Because when you increase the 'load' the sloppyness is taken up by the back > pressure from the cutter. > > This problem has been the downfall of many stepper motor artists. A stepper > might lag as much as 2 steps from the driver output in certain conditions, > and yet recover again if running conditions are normal. But any mechanical > upset in that phase will result in lost steps. > > Happy hunting.
What's the precision rating of the stepper motors? The smaller setting could be less than the motors+mechanicals of the Z axis can handle, and gravity is conspiring with the system to ensure the error is always downward. Can you incorporate a Z height probe/setter and have it automatically recalibrate Z height before each pass? --- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus ------------------------------------------------------------------------------ _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
