Re: CNC Machine for relatively precise wood carving-what would I need?

--- In CAD_CAM_EDM_DRO@yahoogroups.com, "wyatt_meng <wyattmeng@h...>"
<wyattmeng@h...> wrote:

> Hi,
>
> First of all, let me say that I'm relatively new to this.
>
> I'm trying to build a machine for wood carving. It would have to be
> able to cut with enough precision to cut an approximate 1mm groove.
> It would also have to be able to cut 3-dimensionally. What would I
> need? What would it cost? What would I need in terms of computer
> controls? Price isn't much of a problem, so I'm open to any
> suggestions. The work area would have to be about 22" x 16" x 1".
>
> Thanks for your time.

Wyatt. There are more qualified persons on the list that can give
you advice about 3D carving in wood. It sounds however that what you
want to do is more 2.5D; that you want to route designs into flat
wood pieces. I gathered that from your 1" Z specification. Have you
looked at any software design programs? Is your intent more artistic
(signs, plaques, etc) or mechanical (furniture parts, mold masters,
etc). For TRUE 3D you need to be considering a 4 or 5 axis machine.
By telling us what your intended end result is we can give more
concise advice.

The issue with accuracy has a lot to do with cumulative error and
repeatability rather than just raw resolution. You can easily build
a machine that has a resolution of .0001 inch or better but has so
much backlash and flex that it's lucky to hold .1 inch (or worse).
Remember that complex wood carving/routing can consist of thousands
of lines (moves) in g-code and a machine with bad backlash and
excessive flex will give really poor results. I just finished a
carving (.65 inch deep in 1" wood) that was 60,000 lines of code. It
took 4 hours to run on the machine and it only went back to 0,0 three
times in the whole thing!

I know this did not answer your question, but until we understand
your end usage any advice is pure speculation.

I responded because I saw no one else did and it's important that new
members questions get answered. Contact me off list if you want and
I will take the time to relate my experiences in building and
programming 3 different hobby CNC machines.