Re: [CAD_CAM_EDM_DRO] Z axis drive

Ron,
One of the problems is when milling, the tool "can" be pulled down by
the cutting forces! My opinion is that you are better off trying to
minimize the backlash in the drive mechanism as much as possible. On
my RF31, I was able to loosen the attachment screws for the pinion
shaft and move it enough to significantly reduce the backlash. That
along with removing that spring (in my case, it gets in the way of
some of my tooling) and replacing it with a big counter weight. But
if you remove the spring (at least on the RF31, you need to replace
it with some sort of retainer to restrict axial movement of the
pinion shaft. Otherwise, the shaft can move and allow the worm wheel
for the micro feed to disengage and break teeth on the wheel (don't
ask how I know).

Bubba

At 08:01 AM 1/5/2006, you wrote:

>Im doing a conversion on a large, square column, mill, like a RF-45, but
>from Wholesale Tool
>
>The Quill drive has a rewind spring to keep the quill up, and is driven
>down by either a drill press style wheel or a worm gear and small handwheel.
>
>I am considering driving the handwheel with a belt and stepper, and
>hoping the rewind spring can be set strong enough to keep backlash down
>to a workable level.
>
>Has anyone tried this? It seems to me the forces are always cutting down
>on Z, never when retracting, so the spring ought to do it.
>
>ron ginger
>

Bubba

OLDER THAN DIRT
Country Bubba
(Actually the inventor of Country and Bubba)
In God We Trust

LaGrange, GA

http://bellsouthpwp.net/A/r/Arts_home_page/cnc/

[Non-text portions of this message have been removed]