Re: Linear motion design Q

If you put the rails on a beefy flat table, no deflection, as opposed
to unsupported shaft. But this may mean using only gravity to keep
the table from jittering/lifting during a heavy cut. Also putting the
table low relative to the rails will help keep those sideways forces
from "tipping" the table. That's why I asked the original question,
possibly this could allow for some low cost rails...

But also: If you build the X table on saggy rods ;-> , and put the
cross feed on this, then the sag is moot (as long as you don't bind).
Unless it starts bouncing like Galloping Gertie the Bridge
( http://www.nwrain.net/~newtsuit/recoveries/narrows/gg.htm ).
patmat

--- In CAD_CAM_EDM_DRO@y..., "hotaluminum" <zbadone@b...> wrote:
> Chris,
>
> Thanks for pointing out my desing flaws. %^)
>
> I am not looking to build a machine with the higest precision
> possible, but something that will perform what I'm trying to do with
> it. The reason I am leaning towards CRS it that I bought some 3/4"
> round stock (3Ft) and supported it at each end. I hook up a dial
gauge
> in the middle and preceded to press my finger in the middle and
could
> deflect it quite a bit. I was thinking that a piece of 1/4" x 2" CRS
> place on edge (2" flat side facing verticle) with the bearing
running
> on the 1/4 would not deflect as much.
>