RE: [CAD_CAM_EDM_DRO] Re: are 3/4 shafts good for axis ?

Supported rails (say 16mm or 20mm) aren't that expensive these days.
Depends on your budget I guess.

You don't need solid shafts, pipe will work so long as it's supported. Your
two bearings go on one side, and you have wood or whatever on the other
supporting the rail. You can screw the pipe directly to the base, the
bearings will have enough clearance to miss the head of the screw.

If you are putting bearings on angle (at 90 degrees to each other) then your
rail can be another piece of angle (or square pipe), see
http://buildyourcnc.com/mickhcnc.aspx.

The same site, and I can't find the link, has an alternative to v-rail by
simply using flat rail and ordinary bearings.

Even with only 3 inches of travel you are still looking at up to 12" of
rail.

Tony

> My plans are to do wood working. making simple signs, like house numbers.
> ( think large individual letters)
>
> my maximum tool will be a trim router.
>
> I have a CNC mini-mill, so I have no need to attempt to try to do metal.
>
> The cost of 4 BishopWisecarver bearings and needed rails would bump the
> cost of this machine higher than I would like.
>
> I have started looking at taking 2 skate bearings, mounting them on a 45

and

> using home ground steel (also on a 45) as the rail. I know this presents
> tremendous hurdles. one is parallel installation of bearings and rails.
>
> Since I am only expecting 2-3 inches of Z travel, I hope that round shafts
> would not be a problem. I thought about a 6 inch travel, but that would

be

> for foam cutting for lost foam casting. I thing anything would work for
> cutting foam !
>
> Of course, I am re-designing to allow a simple swap out in the future in

the

> event I am not satisfied.
>
> I seem to remember a second source for Vee bearings and rails. now it
> seems that only bishop wisecarver offers them. I wonder if there was a
> patient infringement ???
>
> Anyone know where to get hardened Vee rails for a decent price ?
>
> I am not adverse to getting more than I need. I have a second (smaller)
> machine in the future.
>
> Dave