What the thread found

• A motor that spins uncontrollably when calibrated under load but works fine when removed from the lens may have a loose gear between the potentiometer and output gear
• Under load from the lens gear, pressure increases on the potentiometer shaft, causing the friction-fit gear to slip and lose position tracking
• Testing whether the potentiometer shaft rotates when the output gear turns can confirm whether the potentiometer gear has slipped
• The potentiometer gear in this motor type cannot be tightened as it uses a friction fit and requires replacement if loose

Depends on

• This diagnosis applies specifically to motorized follow focus systems with potentiometer-based position feedback
• The solution requires identifying that the problem persists with the same motor across different control units, ruling out transmitter or receiver faults
• Potentiometer gear replacement requires service-level access to the motor

Gear in this thread

BFD

Same gear or parts

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