Z probe routine drives the Z axis up instead of down

I have a Genmitsu 4040 Pro and when using GSender, the manual Z jog works up and down correctly, but the Z probe routine now drives the Z axis upward to the top instead of down and triggers an alarm. The issue used to work before, wiring has not been changed. Not sure of what to do.

I would go through the gsender set up again. Try going through the Probe config first.

I deleted and reloaded gsender, went thru the settings and it still does the same thing

Well you can change the direction of the Z in the Grbl settings.

GRBL_Settings_Pocket_Guide_Rev_B.pdf

Check $6 and see what it is set at.

ai

  1. Verify Software Probing Options

Certain control programs (like gSender or Easel) require strict adherence to the starting corner settings. [1]

  1. Check the probing interface (often in the lower-right corner of the probing widget) to ensure you have selected the correct starting corner for your material.

  2. Double-check that your probe thickness (or Z-offset) isn’t accidentally set to a negative value in the configuration settings. [1, 2]

  3. Hardware and Wiring Issues

Occasionally, the physical stepper motor wiring or probe connection is flipped. [1]

  1. Make sure your Z-axis probe cable is securely seated in the probe pin on the control board (often labeled Probe, A5, or Z-Limit).
  2. If you are using a custom or DIY touch probe, ensure the crocodile clip is attached to the metal end mill and the magnet/block is flat against the workpiece so the circuit trips correctly. [1, 2]

I’d download UGS and see if that makes any difference.