I have been thinking about a design for a 2 rotary axis gimbaled table for use in a milling machine. So far it is still at the sketch stage, but it’s within the capability of my shop and skills. However, I’m worried about how cutting forces and drive backlash would interact as the cut crossed the axis of rotation. Currently I thinking about a worm and gear to drive the rotation so cutting forces really could not try to rotate the motor worm shaft, but worm shafts and gears typically have a lot of backlash.
Is there an alternative drive connection for rotary joints? For example, ball screws eliminate backlash for linear drives, is there a ball joint for rotary connections? Alternately, spring loaded dual nuts can eliminate/reduce linear backlash so is there an equivalent for rotary joints. So far all I can think of is having two worm drives on opposite sides of the gear, where both were driven at the same rpm but in opposite rotation and spring loaded in the same direction.
I’m quite serious about this project and just joined the group to gain insight into the CNC techniques required. While reading old posts I read the linear motion thread and it triggered the question. Couldn’t find an answer with a search and this seemed like the best thread for the question. As background on me, I practiced mechanical engineering 40 years ago and currently work as an applied mathematician. I have a metal/wood shop and spend lots of hobby time in it.
Tom