1 Topic by lost4good

  • lost4good
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  • From: Lebanon, Pa
  • Registered: 2013-04-10
  • Posts: 5

Topic: Y axis only moves forward

My SD3 developed a problem with the Y axis only moving forward (towards the front of the machine) and not driving backward.
I've had the machine for about a month with no issues other then calibration and tweaking.
Belt tension seems even, and it move smoothly under hand pressure.
I verified the board voltage and it was .529 - no adjustment made
Lubrication appears ok
X and Z axis no issues.

I did swap the Y and Z wires for testing and the problem switched to the Z axis making me think the issue is in the electronics.
When it tries to drive backwards the stepper motor signs until I hit the "Stop Motor" button.  This also happened on the Z axis when I swapped the wires.

Ideas or Thoughts?

2 Reply by ronsii

  • ronsii
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  • From: PNW
  • Registered: 2012-10-28
  • Posts: 1,723

Re: Y axis only moves forward

Sounds like you may have a bad 4988 driver module.

3 Reply by IanJohnson

  • IanJohnson
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  • Registered: 2012-08-07
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Re: Y axis only moves forward

There is a chance that it could be the endstop.  When the wiring fails, it usually makes the endstop act as if it is always switched on.  The motor won't move toward it because it always thinks the axis is at home.

4 Reply by lost4good

  • lost4good
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  • From: Lebanon, Pa
  • Registered: 2013-04-10
  • Posts: 5

Re: Y axis only moves forward

- Solved

Thanks IanJohnson, it ended up being the Y axis end stop.  The metal lever was too tight and caused the end stop circuit to open.  I gently bent the lever out a bit and the circuit closed.  I tested the switch with a meter and it seems rock solid now.
I may order a replacement to have on hand just in case.

Thanks again for the help