Metal antenna rotator
From SatNOGS Wiki
To build this metal antenna rotator you will need a welder.
Bill of materials
Nema23 stepper motor Wormgear 60:1 aliexpress.com/item/Ratio-20-1-self-lock-High-Torque-L56mm-NEMA23-3A-RV30-Turbine-Worm-Gearbox-Geared/32681621498.html aliexpress.com/item/Ratio-20-1-self-lock-High-Torque-L112mm-NEMA23-4-2A-RV30-Turbine-Worm-Gearbox/32681645351.html
Bearing for the az axis 100x135x25 mm : aliexpress.com/item/51120-Thrust-Bearing-100x135x25-mm-ABEC-1-1-PC-Axial-51120-Thrust-Ball-Bearings-8120/32813388761.html
Stepper motor driver : aliexpress.com/item/2-Phase-Stepper-Driver-MA860-DSP-24V-80VDC-or-VAC16-70VAC-Output-6A-Current-NEMA-34/32785076340.html