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Troubleshooting Limit Switch Issues

  • Issue: The machine won't reference.
  • Cause: There may be broken or loose wires, defective switches, or problems with limit switch alignment.
  • Solution: Gather the required tools and perform the following steps.

Required Tools

Some troubleshooting procedures require the following tools. Make sure you have them available for possible use.

  • #1 Phillips screwdriver
  • Flat-blade screwdriver
  • Flashlight to identify correct wires and terminals
  • Needle-nose pliers
  • Short piece of wire to use as a jumper cable

Initial Troubleshooting

Follow these steps to determine on which axis the limit switch isn't functioning.

WARNING! Automatic Start Hazard: The machine could start at any time and injure you. To prevent injury, you must thoroughly read all instructions before you try to complete any procedure.

  1. Power on the machine and the PathPilot® controller.

    1. Turn the Main Disconnect switch to ON on the right side of the electrical cabinet.
    2. Twist out the Emergency Stop button on the operator panel, which enables movement to the machine axes and the spindle.
    3. Press the Start button on the operator panel.
    4. Bring the machine out of reset and reference it.
  2. From the PathPilot® interface, on the Main tab, click REF Z, REF X, then REF Y.

  3. On the Status tab, examine the Notebook section for an error message. The first image shows an error message that indicates a shorted limit switch circuit. The second shows an error message that indicates an open limit switch circuit.

  4. Push in the emergency stop button on the operator panel, which disables movement of the machine axes and the spindle.

    ClosedWatch an example of a shorted limit switch

Do you see limit switch entries in the Notebook section of the Status tab?