Adjusting a Gemco 2006 Series Rotary Limit Switch

Gemco Rotary Limit Switches are commonly found on cranes, hoists, and other machinery where motion is expressed by shaft rotation. There are two types available: a two circuit and a four circuit. The two circuit version has two cams that can be independently adjusted, and the four circuit version has four cams. In this guide, we will adjust a two circuit rotary limit switch, as if we were setting the end points of travel.

What We'll Need

  • Slotted Screwdriver
  • 1/16 hex key (Provided with 2006 Series rotary limit switch; however, it may have been removed.)


  1. Remove the cover screws, then remove the cover.
  2. Remove the hex key from the holder, if it is still there.
  3. Move the machinery so that the shaft is rotated to the desired setpoint. (This could be the fully open position of a door, the top of travel of a crane, etc.)
  4. Note the direction of rotation of the cam as the machinery approaches the desired setpoint.
  5. Identify which snap switch you want to adjust for the set point.
  6. Loosen the set screw for the appropriate cam. The set screws are color-coded, and there's a diagram with color codes inside the cover.
    Color Codes
  7. Identify the adjustment screw for the cam.
  8. Next, move the adjustment screw backwards slightly so that the switch is NOT actuated. If you're adjusting the end of travel, you'll move the cam back toward the middle of travel.
  9. Now, move the adjustment screw toward the set point until the switch is actuated. You should hear the snap switch click.
  10. Tighten the set screw, and verify that the set point is now correct. Adjust if necessary, and repeat this process for any other set points.
  11. Remember to put the hex key back in place, then reassemble the cover

If you have questions about adjusting your rotary limit switch or need replacement parts, please contact us!

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