commercial operators Archives - DDM Garage Doors Blog

How to Set the Clutch on a Commercial Jackshaft Operator

Saturday, January 7th, 2023 at 6:54 pm by Philip Kendall

If you are a garage door contractor who needs to set the clutch on a long row of doors with jackshaft operators, it is important to have a consistent method of adjusting them. This will avoid the extra time required to test, set, and retest each door.…

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How to Replace the Clutch on a Commercial Jackshaft Operator

Saturday, December 31st, 2022 at 1:14 pm by Philip Kendall

In this video, we use a LiftMaster operator to demonstrate how to replace the clutch on a commercial jackshaft operator. The clutch is one of the three safety systems manufacturers build into their operators.

Taking the Assembly Apart

  1. Firstly, disconnect the power from the operator for safety.


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How Commercial Operator Clutches Work

Saturday, December 31st, 2022 at 1:11 pm by Philip Kendall

Commercial Operator Clutches are one of the safety devices that operator manufacturers use to keep their doors from causing injuries or damage. The clutch will slip, which keeps the operator from forcing the door open or shut if something is obstructing it.…

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Counter Wiring for A LiftMaster Operator

Friday, December 18th, 2020 at 5:55 pm by Dan Musick

An operator counter tracks door cycles: one opening plus one closing equals one cycle. To track the usage of a garage door, users often install counters on the operators.

An image of  a LiftMaster operator with an external counter showing 196,491 cycles.
This 24-volt counter shows that the operator has cycled 196,491 times.

One of the more common reasons to track door cycles is to schedule maintenance before the door or the operator needs repairs.…

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How to Adjust a LiftMaster Motor So the Belt Fits

Friday, December 11th, 2020 at 6:33 pm by Dan Musick

Sometimes, replacement v-belts on garage door operators are a different length than the original belt. In this video, we demonstrate how to adjust a LiftMaster motor so that the belt fits properly, even if it is a different length.

If a v-belt is too tight or too loose, you can adjust the motor to get the proper fit.


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How to Replace V Belts on LiftMaster Operators

Friday, December 4th, 2020 at 6:39 pm by Dan Musick

In this video, we demonstrate how to replace v-belts on LiftMaster operators.

There is a safe and easy way to replace operator V-Belts.

For safety, unplug the power to the operator. Wedge a large screwdriver between the belt and the pulley.…

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LiftMaster Model J Drive Components

Friday, November 6th, 2020 at 6:46 pm by Dan Musick

One of the more common LiftMaster operators is the jackshaft operator. The operator transfers energy as torque power from the motor to the counterbalance shaft in order to open a sectional overhead door. When the counterbalance shaft turns, it opens or closes the door.…

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LiftMaster Logic 5 Voltages

Friday, September 25th, 2020 at 3:36 pm by Dan Musick

In most commercial operators sold in the last century, there were two voltages: the incoming line voltage, and the lower secondary voltage from the transformer. This was usually 24-28 volts with alternating current. On rainy days in my early years, this lower voltage would often produce a noticeable shock.…

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Functions of a LiftMaster Logic 5 Control Board

Friday, September 11th, 2020 at 2:09 pm by Dan Musick

Four-wire motors

When I first got into the door business, the most common wiring for a 110-volt circuit consisted of a four-wire motor and two power leads. The two power leads ran straight to the motor. The other wires from the motor could go to either power lead.…

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Counter and Timer Modification for LiftMaster Operators

Tuesday, September 8th, 2020 at 4:10 pm by Dan Musick

In order to test the cycle life of different spring systems, we designed a Counter and Timer Modification for LiftMaster Operators. This modification allows the operator to close immediately after opening and to open immediately after closing. As a result, we can run the operator nonstop for days at a time so that a 10,000 cycle test can be completed in just a few days.…

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