Re: [CAD_CAM_EDM_DRO] Re: Measuring backlash more accurately?

justjuha wrote:

>One thing more for the backlash discussion.
>I'm rebuilding the Cincinnati 10VC-1000 milling machine. There is a
>possibility to brake the movement of an axis when it is not moving
>(original arrangement). I'm going to fit the machine with the Rutex's
>drives and control it with Mach1.
>Is there any chance to implement such feature into the drive such
>Rutex R90 or R997, that it would be possible to enable the brake when
>the servo drive does not drive the servo motor. What I would need is
>just one change-over contact. Any ideas??
>I've asked this from the Rutex without responce.
>As you can see, I am also trying to get rid of the backlash broblems.
>
>

You are trying to get rid of backlash with a brake? Do you mean an axis
clamp?
You really can't do this. A servo system needs to be in a closed-loop
condition.
Activating the brake changes it to open-loop (beacuse torque from the
motor will
not cause any movement) and when you release the brake, it will jump
violently.

A brake isn't a fix for backlash, because the backlash will be there
whenever the axis is
unclamped and moving. If you have ballscrews that are worn, send them
out for a
rebuild. That is MUCH less expensive than new screws and nuts.

Jon