Re: [CAD_CAM_EDM_DRO] Re: EMC and lead screw compensation

Smoke wrote:

> Maybe we should be installing laser positioning devices on the machines now
> to indicate actual backlash "on the fly"? Would that work well with ACME
> screws? That way we could eliminate the use of ball screws altogether.

No, it won't. That might work for a positioning-only system, but not for
any other machining operations. The problem is that the motor would have
to be rapidly hopping from one side to the other of the backlash to constrain
table motion. It can't get from one side to the other of any appreciable amount
ofbacklash quickly, so the table is left freely floating during that interval.
Also, without knowing the exact amount of backlash at that point, the system wouldn't
know when to slow down as it approaches contact, and so it would be banging
violently from one end of the backlash to the other, providing anything but smooth
motion.

Jon