Re: [CAD_CAM_EDM_DRO] Ways, guides etc.

Dear Peter and the forum,

Thanks for the helpful responses. I use one of these pre-loaded assemblies
(that Peter mentioned) for a big gantry cnc plasma cutter I built a few
years ago (12' x 4.5 '). The head of the plasma cutter also incorporates a
drill which is used to provide a start hole for cutting in the middle of
thick steel (5/8) rather than piercing and burning up tips quickly. A
subroutine moves the drill over, then replaces it with the torch when the
hole is drilled. I think it was made by THK or NSK. I forget the name of
the manufacturer, since I got them surplus. The whole rig is very beefy.
The moving component on the assembly I use is about 5 X 3" and the rail is
about 21/4" in width. I think this is the kind of device you are referring
to. But I have had reservations about their stiffness in this application.
In the machine I am making, I want to mount a 1" boring bar on top of the
moving platform (tool holder platform, similar to a crossfeed on a lthe).
This boring bar would reach out beyond the end of the rail assembly about 9"
and hold a true cut, hopefully near .001 inches while making cuts of .010
"deep and 1/32 " wide in aluminum. What do you folks think? Could I get
that kind of performance out of that kind of assembly in a machine that is
going to work about 3 hours a day, six days a week with a service life of at
least 2 years, or would I do better to build up dovetail or box ways? If the
prefabbed unit will do the job, I think I would prefer it, if it is only 1.5
times the cost of the alternatives.

I also like the idea Ballendo has for spinning the ball screws. It would
allow the drive to be tucked away under the rail. Thank you for those
thoughts.

Tom Eldredge, Trustee

----- Original Message -----
From: Sven Peter, TAD S.A. <peteryco@...>
To: <CAD_CAM_EDM_DRO@yahoogroups.com>
Sent: Tuesday, January 30, 2001 1:34 AM
Subject: Re: [CAD_CAM_EDM_DRO] Ways, guides etc.


> > I could purchase the metal so that I could simply bolt the rails to a
flat piece of steel, insert a brass shim for adjusting width etc...
> >
>
> Nowerdays many toolmachines are made of linear guides with pretentioned
linear bearings.
> They are a little expensive but extremly accurate, smooth sliding and
stiff. All you have to do
> is surface grind the base plate, mount the first guide and indicate the
second one. I get mine from
> NSK or SNR. They have including full equiped sets they call monocarrier
(guide rail, ball screw and
> end plates with tapered bearings ready assembled)
> (My supplier: TMH (Technical Marine Supplier near Hamburg, Germany) - Mr.
Michael Machacek, telfax 0049-4101-45076, email: TMH-Halstenbek@...
> This guy is great on special bearings for spindles and faster than many
others.
>
> Good luck
> Sven Peter
>
>
> [Non-text portions of this message have been removed]
>
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