2011Follow Focus forum
Heden M21VP motor difficulty turning iris ring and stiffness when unpowered
15 years old. Gear and prices may have changed since.
What the thread found
- A small Heden M21VP analog motor used for iris control may develop resistance when turning the iris ring on non-stiff lenses, and the gear becomes difficult to turn by hand when power is disconnected
- The larger Heden motor turns easily by hand when unpowered, suggesting the M21VP may have a different mechanical characteristic or potential mechanical issue
Depends on
- The user could not recall the baseline behavior of the motor from prior use
- No resolution was provided in the thread regarding what caused the stiffness or whether service corrected the issue
- Specific model comparison details between the small and large motors are limited