Re: Room for everybody (still)

Bob,

A miter cut (in 4/4 wood; about 13/16") that is off .012 is visible
to the naked eye. I get frustrated with the mistaken belief that 1/32
is good enough for wood... There are many things made of wood that
require "thousandth" precision. Not generally ACCURACY, but
definitely REPEATABILITY. And not just inlay.

Let's take that wooden panel off by ONLY .02 that you mentioned. Now
we'll "wrap it" with 4 pieces of wood, picture frame like. If these 4
pcs. are NOT ALSO off by .02 you will have what nearly everyone will
agree is a sloppy job!

Please understand that we are happy that you and others have found
success with threaded rod. (I have too!) But that does not mean that
the points Chris (BOTH Chris S AND Chris L) raise go away...

And I always say, you are better off KNOWING what trade-offs you are
accepting, than to blindly assume that it will work as you
expect/need. Chris is just pointing out some of these tradeoffs.

If you can live with these trade-offs, then please make a simple
machine rather than waiting for the "perfect" machine (which doesn't
exist anyway, IMO). I cannot express how much we are in agreement
about this "okay-to-build-the-simple-machine".

But some DO NEED better than "hardware store threaded rod"
positioning, with "heater pipe" rails; and for them, we're here to
help spread the knowledge they need to complete THEIR project(s).

Chris L sells plans for a more expensive precision machine, much the
same as John K sells plans for inexpensive machines. Different
customers. There's room for everybody.

Hope this helps.

Ballendo

--- In CAD_CAM_EDM_DRO@y..., "cncdxf" <cncdxf@a...> wrote:
> Chris,
> A 1/4-20 rod with a 1/2" thick Piece of Delrin has
> almost no backlash. The original post asked if threaded rod
> would be good for a machine that cuts wood. Try talking to
> a woodworker in thousandths. Someone doing inlays now that's
> different. Making a wooden panel that is off by .02 is
> incredible. The threaded rod when correctly used is even
> more accurate. The orignal poster was talking wood, not
> steel, not a printing machine, wood!
> Bob
>
> --- In CAD_CAM_EDM_DRO@y..., Chris L <datac@l...> wrote:
> > Hey,
> > I read this whole post too.
> >
> >I just know that .006 turns to .012 on direction changes. When
> >you try to cut some really nice text into a nice sign blank and
> >you end up with "stepping" along all your edges in Z, you end up
> >wishing you had something more accurate.
> >
> >The "thrill" of CNC does not seem to last as long when you profile
> >around the outside of a signblank and now find you need to sand
> >for an hour just because the vertical edges are not straight.
> >
> >So, that's why I suggested spending a little more money up front
> >on a better screw and nut setup, rather than the hours you will
> >spend either making a nut, OR , sanding and filing your new sign
> >into shape.
> >
> >But, There are no laws ! You can use threaded rod if you'd Like !
> >
> >Chris L
<snip>