Re: Looking for short ballscrew for Z axis

I would be a little carfull with the Z axis as in moving the head.
As i understand it you loose the ability to tilt the head. And
secondly you loose some ridgidity. I would power the knee before i
moved the head.


Wally K.

--- In CAD_CAM_EDM_DRO@egroups.com, Hugh Currin <currinh@O...> wrote:
> Jon:
>
> At 05:02 PM 11/30/00 -0800, you wrote:
> >I'm thinking hard about making a Milltronics type slide for my
knee mill
> >after looking at one up close. I've got some nice THK linear rails
for
> >the slide, but looks like I need about a 1" ball screw for the Z.
> >I'd really rather not buy a 72" length of screw. Before I start
shopping
> >around for some cut lengths, I thought I'd ask if anyone on the
list has
> >an 18" or so length of 1" ground screw stock with a .2 or .25
pitch, and
> >a ballnut that they'd be interested in selling.
> >Need not be preloaded, I doubt backlash will be a factor with the
full
> >weight of a BP type head holding things down.
>
> Sorry, I don't have any to sell. But I'm sure you can get shorter
> lengths from the Mfg.
>
> I really like this concept for a Z axis. At first glance I thought
a
> round linear ball bearing slide would be less expensive than linear
> rails, but if you have them already. How do you figure you need a
1"
> ballscrew? This seems large for this 6 or 8" travel. What does a
> Bridgeport Head weigh?
>
> Please keep us informed, I'm really interested in how this works and
> if you run into any problems.
>
> Thanks.
>
> Hugh Currin
> Klamath Falls, OR