Re: [CAD_CAM_EDM_DRO] Re: Ball screws for CNC plasma cutters

If you've seen a plasma cutter then you have also seen all the particulate slag and grit that is generated. This grit can play havoc
with any type of screw. A better solution is a rack and pinion drive. If the teeth on the rack are positioned vertically or upside
down the grit problem is minimized. Racks can also be of unlimited length. Screws on the other hand suffer from whip lash at longer
lengths. My 72 x 126 inch CNC plasma, with rack and pinion drive, holds the same tolerances it did when it was new fifteen years
ago.

Jay Hayes

Smoke wrote:

> I'm just wondering...I've seen plasma cutters in use. It appears to me any
> attempts to hold
> REALLY CLOSE tolerances seems to be a lot of overkill. I've never seen a
> plasma cutting torch
> yet that will cut a really smooth edge, hence the lack of necessity for
> holding close tolerances.
>
> With this though in mind, i don't see why a person couldn't use threaded rod
> for the lead screw?
> Manufacturing an "antibacklash nut for this would be as simple as placing a
> heavy spring between
> a couple of hex nuts which are trapped to prevent rotation.
>
> I've even seen commercial nuts (used on acme screws) made this way.
>
> Smoke
>
> -----Original Message-----
> From: ozzietwo2001@... <ozzietwo2001@...>
> To: CAD_CAM_EDM_DRO@yahoogroups.com <CAD_CAM_EDM_DRO@yahoogroups.com>
> Date: Sunday, February 11, 2001 10:22 PM
> Subject: [CAD_CAM_EDM_DRO] Re: MillWizard + MaxNC-10, SuperCam &
> Millwizard...
>
> >Tracy,
> >I've found the website for Techno-isel and have found mountains of
> >interesting stuff, but it's daunting to try wading through it all.
> >Can you give us an idea of prices; for instance your 20" table, and
> >if you know, ball screw and nut prices.
> >
> >Thanks,
> >Jerry
> >
> >
> >
> >
> >One major "upgrade" I've
> >> made is using 20" X & Y tables from techno-isel to give me more
> >area
> >> to work with. It works great but really needs stronger stepper
> >motors
> >
> >
> >
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