Geared PAN/TILT
Geared PAN/TILT
I designed this Pan/tilt for use on my robot (FRED). The pan base is supported by plastic bearings & the tilt servo is geared to the top shaft, rather than the more common direct drive.
The advantage of gearing the tilt is threefold:
Greater torque available due to 2.7/1 gear ratio,
Main shaft is supported by two ball bearings.
Servo backlash is reduced by factor of 2.7, less any slop in the printed gears (minimal)
The pan section is direct drive, but is supported by plastic bearings, removing excessive side loads from the pan servo.
Overall result is a strong & stable pan/tilt mount.
Control of the two servos is via RC interface or microcontroller.
This is my design & files have been shared on Thingiverse.
Please note: Nuts are provided in the tilt platform (3mm nylock), but no other hardware is supplied.
Product Specification
Material of manufacture: ABS plastic
Base & uprights infil: 50%
Tilt shaft, main gear & pinion infill: solid
Overall height: 76mm
Height, bottom of base to top of tilt: 51mm
Base dimensions: 71.5mm x 55.8mm
Base mounting holes positioning: 56mm x 46.5mm
Tilt head mounting holes: 26.5 x 29mm
Weight: 125 grams
Pan servo, direct: Turnigy� TGY-4409MD DS/MG 9.45kg / 0.11sec
Tilt servo, geared: Corona 939MG Digital Metal Gear 2.7kg /0.13sec
Tilt gear ratio: 2.7/1
Tilt shaft bearings: 2 x MR106 with rubber seals
Base mounting holes: 3mm counterbored for socket head
Tilt platform mountings: 3mm captive stainless nylock nut
If more information is required, please contact me via my contact page.
Important Information
The nuts used in the tilt platform are stainless 3mm nylocks.
They don't react well to overtightening.
I've used nylocks to prevent loosening due to vibration.
Damage to nuts won't be covered under warranty (easily replaceable).
Due to the gear ratio, the range of movement of the tilt is reduced to approx 60 degrees MAX.
In reality, if using RC gear, the movement will be less due to the servo signal range being limited by the RC transmitter, even at high rates.
I have set the center positions as close as I can, but they are not perfect. Some adjustment using firmware or RC subtrim will be required for perfect centering.