pic: 1747 Turret Close up
 

Re: pic: 1747 Turret Close up
 

i like the use of ball casters for that big sprocket, it is hard to tell so i'll ask instead of guessing, is that also how you help withstand the forces generated at the rotation point?

Re: pic: 1747 Turret Close up
 

Yes the "ball transfers" help distribute the forces away from the rotation point. The "ball transfers" were chosen because they were a low friction method of supporting our arm uprights which are mounted to the sprocket. They also help reduce the amount the arm rocks back and forth when fully extended.