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I have a strange random motor skip.
checked all connectors and wiring.
Thought problem was bad factory wiring where it enters motor, so I replaced all the motors and it still does it.
weird also that is does it more often going slow vs. fast.
pulleys are tight. belts are tight. arms are not binding.
any ideas what to check?

my pulleys are 30 tooth not 20 like the MAX... I started with Olys latest Repetier firmware config for the MAX and adjusted mechanical settings from there.
could something weird mathematically be going on due to the larger pulleys?
the steps per does figure out to a odd number, 53.333333

I was thinking of tweaking these values...
/** \brief Number of segments to generate for delta conversions per second of move
*/
#define DELTA_SEGMENTS_PER_SECOND_PRINT 225 // Move accurate setting for print moves
#define DELTA_SEGMENTS_PER_SECOND_MOVE 80 // Less accurate setting for other moves

or changing the microstepping to 8 instead of 16 to see if that has any effect, good or bad.

... but only on the Z tower? The only thing special about that tower is that the motor rotation is in the opposite direction. So, I can suggest three approaches:

1) Figure out why having the motor in the opposite direction might matter

2) Look elsewhere at the mechanical setup for differences

3) Try to make the problem worse, and if you succeed think about why you succeeded. Examples: add drag, add weight to the cheapskate, decrease the voltage to the motor, increase/decrease the belt tension, etc.


Good luck,
Dan

dtgriscom wrote:... but only on the Z tower? The only thing special about that tower is that the motor rotation is in the opposite direction. So, I can suggest three approaches:

1) Figure out why having the motor in the opposite direction might matter

2) Look elsewhere at the mechanical setup for differences

3) Try to make the problem worse, and if you succeed think about why you succeeded. Examples: add drag, add weight to the cheapskate, decrease the voltage to the motor, increase/decrease the belt tension, etc.


Good luck,
Dan

Thanks for the suggestions.
What makes it worse is slowing down.
Actually the other tower have the same binding jerk, but the Z is the worse one.
hmmm, I should change orientation of part and see if Z gets better.

bvandiepenbos wrote:What makes it worse is slowing down.
Actually the other tower have the same binding jerk, but the Z is the worse one.

Could you use Repetier-Host to slow down motion, and then move the effector platform up and down slowly (in the real Z direction)? (I don't know what the G-code for this would be...)

Then, while it's slowly moving from the bottom to the top, you could play with the belts/motors/bearings and perhaps see what the issue is.


Dan