CM Lodestar Limit Switch Adjustment Procedure

Posted by Jon Fuchs on

How to adjust the CM Lodestar Limit Switch. The limit switch setting allows the operator to set an upper and/or lower limit for hook travel. 

For safety purposes, the following modifications shall only be made by a CM factory trained and certified hoist technician. 

LIMIT SWITCHES

If you've already verified the limit switch's functionality according to the instructions on page 10 of the manual, and find that it's not working correctly or failing to automatically stop the hook at the desired position, follow these steps:

1. Disconnect the hoist from the power supply.
2. Remove the back cover, as shown in Figure 13.
3. Locate the upper and lower limit switches on the fiber insulator.
4. Loosen the screws to allow the guide plate to be moved out of contact with the traveling nuts, as illustrated in Figures 16 and 17.
- For Rotatable Limit Switches, gently pull on the guide spring to disengage the travel nut, as shown in Figures 16A and 17A.

Figure 13. Limit Switches are located under the frame cover (1) for all hoists. 

CM Lodestar Limit Switch Cover

--------------------------------------------------------------------------
Figure 16. Limit Switch Location for Models A thru H-2. 

 CM Lodestar Limit Switch Adjustment

  1. Switch Sub Assembly
  2. Switch Shaft
  3. Moving Nuts
  4. Guide Plate
  5. Guide Plate Screws

------------------------------------------------------------------------

Figure 16a - Rotatable Limit Switch Models A thru H-2

CM Lodestar Rotatable Limit Switch Adjustment

-------------------------------------------------------------------------

Figure 17 - Lodestar Limit Switch, Model J thru RRT-2

CM Lodestar Limit Switch, Model J thru RRT-2

  1. Switch Sub Assembly
  2. Switch Shaft
  3. Moving Nuts
  4. Guide Plate
  5. Guide Plate Screws

------------------------------------------------------------------------------

 CM Lodestar Limit Switch Breakout Diagram

-------------------------------------------------------------------------------

Figure 17a. CM Rotatable Limit Switch, Model J thru RRT-2

CM Lodestar Rotatable Limit Switch Model J - RRT-2

 

Adjusting the Upper Limit Switch:

  1. Consulting Table 6 Guidelines: Review the specifications provided by the CM Lodestar Classic series to determine the minimum distance (dimension "A") between the top of the hook block and the bottom of the hoist for the safest operation. (see table 6 below) 

  2. Power Supply Reconnection: Once reviewed, reconnect the CM Lodestar Classic series chain hoist to its power supply.

  3. Positioning the Hook: Gently maneuver the hook to your desired upper position, ensuring the hoist operates smoothly without any load.

  4. Disconnecting for Adjustments: Disconnect the hoist from its power supply to make necessary adjustments.

  5. Adjusting the Traveling Nuts: Adjust the traveling nuts by moving one closer to the other to increase the hook's travel and vice versa. Rotate the nut nearest the "UPPER LIMIT SWITCH" until you hear an audible click indicating the switch has opened. Rotate it an additional full tooth towards the switch.

  6. Securing Guide Plate: Shift the guide plate to the subsequent slot and fasten the screws securely.

  7. Verification of Upper Limit: Reconnect the CM Lodestar Classic series chain hoist to its power supply. Lower the hook by approximately 10 inches and then cautiously raise it until the upper limit switch halts its upward movement. Ensure the stopping point aligns with your desired upper position; if not, repeat the process.

  8. Double-Checking the Setting: To validate the adjustment, lower the hook by approximately 24 inches (609 mm) and then guide it to the upper limit while holding the upward control.

  9. Refinement Options: If further adjustment is required, consider inverting the guide plate in Step 10. This adjustment offers changes similar to half a notch. Refer to the CM Lodestar Classic series specifications (table 6 below) for specifics on the Hook Travel Per Notch of the Limit Switch Nut. When inverting the guide plate, you might need to select the adjacent notch to the one used initially.

 

 Table 6 - Hook Travel According to Notch of Limit Switch Nut (TPI=44)
Max Length of Lift Hook Travel Per Notch A in. (mm) B (links)
Model ft. (m) in. (mm) Min. Min.
A,A-2,C,C-2
204 (62.2) 1-5/16 (33.3) 1-1/2 (38.1) 6
AA, AA-2 385 (117.3) 2-1/2 (63.5) 2 (30.8) 6
B,B-2,F,F-2 102 (31.1) 11/16 (17.5) 1-1/2 (38.1) 6
E,E-2,H,H-2 47 (14.3) 11/32 (93.1) 1-3/4 (44.5) 6
J,J-2,L,L-2 125 (38.1) 3/4 (19.0) 1-1/2 (38.1) 8
JJ,JJ-2 254 (77.4) 1-15/32 (37.3) 2-1/2 (63.5) 8
LL, LL-2 254 (77.4) 1-15/32 (37.3) 1-1/2 (38.1) 8
R,R-2 66 (20.1) 3/8 (9.5) 2-1/2 (63.5) 8
RR,RR-2 125 (38.1) 3/4 (19.0) 2-1/2 (63.5) 8
RT,RT-2 44 (13.4) 1/4 (6.35) 2-1/2 (63.5) 8
RRT,RRT-2 83 (25.3) 15/32 (11.9) 2-1/2 (63.5) 8

 

 Adjusting the Lower Limit Switch:

  1. Consulting Table 6 Guidelines: Examine the specifications provided by the CM Lodestar Classic series to identify the minimum number of load chain links (dimension "B", Table 6 above) that should be present between the loose end link and the hoist frame. This determines the lowest acceptable hook position for safe operation.

  2. Re-establishing Power Connection: After noting the specifications, reconnect the CM Lodestar Classic series chain hoist to its power source.

  3. Positioning the Hook: Guide the hook down to your desired lower position, ensuring the hoist operates smoothly and securely without any load.

  4. Disconnecting for Adjustment: Safely disconnect the hoist from its power source to proceed with adjustments.

  5. Adjusting the Traveling Nuts: Modify the traveling nuts by bringing one closer to the other to extend the hook's travel, or further apart to reduce it. Rotate the nut closest to the "LOWER LIMIT SWITCH" until you hear a distinct click, indicating the switch has been activated. Rotate it an additional complete tooth towards the switch.

  6. Securing the Guide Plate: Move the guide plate to the adjacent slot and firmly secure it with screws.

  7. Verifying Lower Limit: Reconnect the CM Lodestar Classic series chain hoist to its power source. Elevate the hook by about 10 inches, then cautiously lower it until the lower limit switch halts its descent. Ensure this stopping point matches your intended lower position; if discrepancies arise, revisit the adjustment steps.

  8. Validating the Setting: For thoroughness, elevate the hook by approximately 24 inches (609.6 mm) and then guide it to the lower limit while keeping the downward control depressed.

  9. Refinement and Further Adjustments: If additional tweaking is needed, consider inverting the guide plate's orientation in Step 10. This maneuver provides adjustments akin to half a notch. Delve into the CM Lodestar Classic series specifications for specific details on the Hook Travel Per Notch of the Limit Switch Nut. When making adjustments, you might find it beneficial to choose the neighboring notch to your initial selection.


Share this post



← Older Post