See http://BrainRight.com/Projects/FourthAxis for more details. In this video I build the main drivetrain components of a 4th axis assembly for my CNC machines, using a harmonic drive gearbox to get precise angular positioning and high torque with low backlash.
I'll finish up the assembly in the Part 2 video: https://www.youtube.com/watch?v=xaEhkF9S0mY
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