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Job Execution Issues

Use this page when a job won’t start, stops unexpectedly, or you see position or feed-rate problems.

Job won’t start​

Symptoms: Start does nothing, or you get an error before motion.

Checks:

  1. Connected — Controller connected? Check connection status in the UI.
  2. Not idle — Controller must be Idle (not Hold, Alarm, etc.). Reset or clear any alarm first.
  3. File loaded — G-code file loaded and visualizer shows a toolpath?
  4. Work zero — Work zero set for the axes your job uses? Unset zero can block start or cause undefined behavior.
  5. Homing — If your workflow requires homing, run Home All first. Grbl: homing enabled ($22=1).
  6. Spindle/router — If the job expects the spindle on, ensure it’s ready (or that you’re not blocked by a “spindle not running” check, if any).

Job stops unexpectedly​

Symptoms: Job runs then stops partway; controller may be in Hold or Alarm.

Checks:

  • Console — Read the console for error, alarm, or limit messages. Grbl errors often include a code (e.g. Limit).
  • Limit switch — Hitting a limit stops the job. Jog off the limit, clear the alarm, re-home if you use homing, then re-zero and restart from a safe place.
  • Overheating / stall — Motor or driver overheating can trigger a fault. Let it cool, check wiring and current, then retry.
  • G-code — Odd or unsupported commands can cause a stop. Check the line number in the console and inspect the G-code around it. See G-code compatibility.

Position errors​

Symptoms: “Position lost”, “Homing required”, or clearly wrong positions.

Checks:

  • Homing — If the controller requires homing after reset, run Home All and ensure it completes.
  • Work zero — Correctly set for this job? Wrong zero causes wrong placement.
  • Units — G-code in mm vs inch must match machine/config. Check CAM output and controller $ settings.
  • Steps per mm — Controller firmware (e.g. Grbl $100–$102) must match your machine. Wrong values cause wrong distances.

Feed rate issues​

Symptoms: Moves too fast, too slow, or feed override has no effect.

Checks:

  • G-code F values — CAM sets feed rates. Check the G-code for F and that it’s in the expected units (mm/min or inch/min).
  • Controller feed override — Some controllers support override. Ensure it’s not at 0% or 200% if you see unexpected speed.
  • Max feed in firmware — Controller has max rate limits. Exceeding them can cap or fault.

Next steps​