2005Brackets/Widgets forum
Attaching focus teeth or motorized gears to a dimmer knob on a ring light
21 years old. Gear and prices may have changed since.
What the thread found
- J-B Weld epoxy can secure focus teeth or gears to smooth knobs but requires surface preparation with sandpaper and creates a permanent bond that is difficult to remove
- A thick rubber band wrapped around the knob can provide grip for gear engagement, optionally with plastic washers attached to the knob exterior to help keep the band in place
- Custom Delrin gear rings carved to specific knob diameters are available from specialty optical manufacturers, typically costing around 50 dollars
- An alternative electronic solution involves breaking out the potentiometer wires, extending them with thin wire, and resoldering to avoid mechanical coupling to the physical knob
- The manufacturer of the ring light may be able to supply a geared knob replacement since similar requests have been made by other users
Depends on
- J-B Weld adhesion may be poor on very smooth or shiny plastic surfaces without prior sanding
- The rubber band method is informal and may not provide reliable motorized control
- Custom gear rings require knowing the exact knob diameter
- The electronic solution adds wiring to the rig and changes the control mechanism
- Discussion involves equipment from 2005 and may reference products no longer available