Re: [CAD_CAM_EDM_DRO] dual function lathe spindle

scyvt wrote:

> An Emco CNC lathe with live tooling that was in a school shop I had access to a few years ago seemed to mechanically switch between these two drive systems to alternate functions, perhaps with electromagnetic clutches. However, lately there seem to be videos on the web showing both lathe and 4th axis spindles making this switch between functions seamlessly. The only sort of drive that I can possible imagine doing both would be a servo drive, but holding a static position would be problematic, as the servo motor, unlike a stepper, would be constantly hunting, wouldn't it?
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Servos ARE constantly hunting, anyway. The trick is to make sure the
hunting is of such small magnitude it doesn't bother what you are trying
to do. Often just a higher resolution encoder is needed to reduce the
magnitude of the movement.

Jon