Bird Manufacturing and Design, LLC
100 Station St. · Johnstown, PA 15905
Phone: (814)288-6464 · Fax: (814)288-4455
Zipline Balanced Booms
Boom Balancing Procedure
* The Zipline Balanced Boom uses a compression spring to balance weight loads. This spring is housed in a separate spring retainer housing on the Zipline Balanced Boom. The spring is designed to balance a load of the following:
Boom Arm
Wire Drive Head Assembly
Feeder Mount Bracket & Cage Assembly
Gun & Cable Assemblies
Electrode & Control Cables
Electrode Conduits & Gas Hoses
The compression of the spring is adjusted at the factory to accommodate the most typical loading conditions. The best condition of balance may vary depending on specific load requirements.
* These instructions are intended to show the user how to adjust the compression spring, should it be necessary due to an increase or decrease in loading conditions. The instructions are as follows:

  1. Re-install the red spring rod shipping support between the top of the spring retainer housing and the nut at the bottom of the clevis on the spring rod.

  2. Remove the spring retainer cap at the bottom of the spring retainer housing by removing the four bolts which hold the spring retainer cap onto the spring retainer housing.

  3. Loosen the locking nut on the end of the spring rod. Loosen the locking nut enough to permit loosening or tightening of the adjusting nut which is the nut held in place by the locking nut.

  4. If the boom has a tendency to drift downward after being pushed up, it will be necessary to increase the spring compression by tightening the adjusting nut mentioned in step “C”. If the boom has a tendency to drift upward, it will be necessary to decrease the sppring compression by lossening the adjusting nut mentioned in step “C”.

  5. After making the above adjustments, do the following:

    1. Re-tighten the locking nut loosened in step “C”.

    2. Loosen the friction control knob.

    3. Remove the spring rod shipping support installed in step “A”.

    4. Pull the boom down to a position which is horizontal, using a rope of suitable strength. Loosen the grip on the rope enough to see whether or not the boom is balanced. The best condition of balance is obtained when the boom rises an inch or so when the pull on the rope is loosened.

    5. Tighten the friction control knob to “control” this slight upward movement.


  6. Re-install the spring retainer cap removed in step “B”.