One of the more common LiftMaster Operators is the jackshaft operator. How does the torque get from the motor to the counterbalance shaft of the sectional overhead type door? In this video, we trace the torque as it moves through the LiftMaster Model J drive components.…
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In our video, we demonstrate an easy method for troubleshooting LiftMaster operator error codes.
The product manual covers a variety of codes, but in our video, we cover the four major problems that occur in an estimated 80% of operator failures.…
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Often when a garage door will open but not close, the cause is a misaligned eye or a broken wire. On residential doors with LiftMaster openers, the quickest test is to check the eyes on both sides. If both lights are on, the eyes should be performing correctly.…
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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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Installers and salesmen order sectional door operators to match the operator voltages to the voltages in the buildings. Sometimes salesmen order operators with the wrong voltage, and the operator voltage needs to be changed. This is done by changing the wires at the motor as long as the building voltage was 110 or 220 volts.…
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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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In order to test the cycle life of different spring systems, we designed a Counter & Timer Modification for LiftMaster Operators. This modification allows the operator to close immediately after opening and to open immediately after closing. This, in turn, allows the operator to run 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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Garage door opener limit switches electrically limit the door travel as it opens and closes. These switches “tell” the opener or operator when to stop.
The most common limit switch comes in most of the Sears, Chamberlain and Liftmaster openers made since the early nineties.…
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Commercial door operator manufacturers have designed three standard safety systems.
First is the mechanical clutch that slips when the door is obstructed.
The second design is the eye sensor system.…
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YES, WE'RE OPEN FOR BUSINESS! DDM is considered a life-sustaining company because we are an internet retail company that provides essential products. Due to the recent outbreak of Coronavirus, however, we are changing our local order pickup policy at our West Chicago location. To pick up an order you will need to order first. The quickest way is to order in advance through our online shopping cart. There you can select the local pickup option. Or, you can call 630-293-1337 for assistance, to confirm availability of parts, and to place your order. Once ordered, your parts will be available for pickup in the lobby of our north side front entrance. Longer items will be picked up on the south side loading dock. Please honor the six foot social distancing rule. Thank you for your patience and understanding as we all navigate this challenge together. More information is available on our blog titled DDM Adjusts to the COVID-19 Coronavirus. In the same article you will also find documentation and an answer to the question: "Is a garage door repair company a life sustaining business?"
PLEASE NOTE: DUE TO COVID-19 SHIPPING TIMES ARE NOT GUARANTEED, EVEN ON NEXT DAY AND SECOND DAY SHIPMENTS. NORMAL TRANSIT TIMES DO NOT APPLY.
