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[khobar]

Hi guys,

It's been a while. I am trying to get my AstroEQ to drive a belt-modded Exost2-GT mount. Presently, I am using .9 degree/step motors, 0.9A. Gear ratio is 4:1. Mount has 144 teeth, etc.

The driver IC I'm using is an A4988. uStepping is set to 16, slew rate 620 IIRC.

Mount currently has nothing on it, no counterweights, no scope, just the counterweight bar.

I am simulating night and position to see if the mount will point towards M42. This helped me figure out RA was reversed. However, I noticed DEC would stall near the end of the slew. The axis is effectively unloaded and turns freely when the clutch is disengaged.

Any idea what is likely the cause? Any suggestions for further testing?

Thanks!

[TCWORLD]

Stalling usually either means the current limit is set too low, or the slew rate (e.g. goto speed) is too high for the motors to keep up with.

If it's stalling on decelleration, it's possible that the motor is hitting some sort of resonant frequency that causes it to stall, but that would still likely would mean the motors are being used at their limit.