Re: not stiff enough!

I'm machining wood.

For instance, put a 1/16" bit on the trim router I'm using, and
program it to make a 3/16" round hole. The hole isn't much bigger
than the bit. This is in 1/4" hardboard.

Or, cut small squares with the same bit, the sides will be odd shapes
because of side loading from the bit.

Used a 3/4" bit in an attempt to find what the machine thinks is the
zero plane. Was getting up to 1/8" movement in the bit do to side
loading. Went to a 1/4" bit, worked much better, but still noticable
ridges in a nice spiral patern, again caused by side loading on the
bit.

I did notice that a low value for acceleration helps let the
bit "settle" when making cuts...

Maybe I'll try real light cuts, say 1/16", and see how it responds..
Certainly have more time than money.

Thanks.

--- In CAD_CAM_EDM_DRO@egroups.com, Joe Vicars <jvicars@c...> wrote:
> Rich,
> Take lighter cuts. Your machine looks much better than alot of
the "kits" available right now. I think you're just taking too
> heavy of a cut. You can also experiment with cutters. Different
cutters will produce significantly greater side loading than
> others.
> I guess you should be specific about how much flex is too
much. You are machining wood right?
>
> Richard Spelling wrote:
>
> > I built this cncrouter:
> > http://www.spellingbusiness.com/robot.jpg
> >
> > X is 1 1/4" shafts, 60".
> > Y is 1" shafts, ~40"
> > Z is 1/2" shafts, 18"
> >
> > The problem I'm having is that it's not very stiff. I realized
there would
> > be some flex in the unsupported shafting when I built it, but I
didn't
> > realize it would be as bad as it is.
> >
> > I have 3/4" for Z, which would take care of some of the stiffness
problem,
> > but I can grab the top of the top of Z and move it by hand and
the 1" shafts
> > will flex visibly.
> >
> > My current back to the drawing board effort focuses around theses
items:
> >
> > 1) use the 3/4" shafting for Z
> > 2) move the Y shafts further appart to reduce leverage
> > 3) possibly rotate Y shafts 90 degress to bring the "top" one to
the same
> > level as the bottom one
> > 4) use the 1 1/4" shafting for Y
> > 5) use the 1" shafting for X, drill and tap holes for support
posts
> >
> > and maybe
> > 6) use open bearings an ALL shafts, attach "angle iron" steel
supports and
> > cross bracing.
> >
> > comments and suggestions requested!
> >
> > Richard Spelling, http://www.spellingbusiness.com/boats
> > >From the muddy waters of Oklahoma
> >
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