Re: Machine geometry

Gar,

The 4 by 4 was built using Item aluminum extrusions. The X and Y rails were
Ina bearings on 14mm shafting (top and bottom). The Z axis uses THK
bearings with about 6 inches of travel.

In order to reduce the racking of the gantry, I built a double cable system
to counteract the racking. Now when I push on one side, the cables will
pull on the other side. This has helped a great deal.

After I build my new 2 by 2 fixed bridge system, I will retrofit my 4 by 4
with THK rails and bearings on the X and Y.

Bob

----- Original Message -----
From: Gar Willis <garfield@...>
To: <CAD_CAM_EDM_DRO@onelist.com>
Sent: Saturday, June 12, 1999 9:58 PM
Subject: Re: [CAD_CAM_EDM_DRO] Machine geometry


> From: garfield@... (Gar Willis)
>
> On Sat, 12 Jun 1999 21:37:10 -0500, "Robert Campbell"
> <rcamp@...-dfw.com> wrote:
>
> >I have a 4' by 4'
> >moving gantry system which has some play in it. I am currently building
a
> >2' by 2' fixed bridge cnc router that should be very ridged. I cut a lot
of
> >Corian and wood parts.
>
> I missed the description of your 4X4, if you posted it. Could you say
> how it was constructed, as to guides used, gantry framing/structure, and
> also positioning method/hardware? I'd most like to hear any insights
> you've gained from this "some play" which you've experienced. Most
> helpful would also be the Z-travel range you've worked with on your 4X4,
> or do I get your drift correctly, that it's even in just the X-Y plane
> that you have this play?
>
> TIA,
> Gar
>
>
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