Re: [CAD_CAM_EDM_DRO] help putting together a complete system

airport@... wrote:

> I'm not lazy. This is hi-tech for me! I do sculptures. I want a
> low cost cad/cam system to digitize subjects and carve the busts with
> a cnc machine. Low cost is essential. How much am I looking at in
> your opinion? Could anyone help me piece together a system from
> start to finish? Thank You, Joe Hogan

This is not easy! I have looked into it. There are a couple of ways to go.

1. The definitely will work way :
Get a laser or light bar 3-D scanner. About $10000, but the price may
be coming down.
Get a good CAD/CAM system that handles extremely complex 3-D
surfaces well, and can generate efficient tool paths that don't gouge
the work, and does 4-axis contouring. Expect to pay, perhaps, $8000
Get a decent 4-axis machine, ie. a Sherline with indexing head for the
smaller busts, and maybe something a bit bigger, like a Max-NC
if you want to do life-size. Probably around $3000 minimum

Oops, you wanted cheap, didn't you.

2. I really don't think this will work, but it could be done.
Get a good digital camera, with an optical zoom lens, and some
sort of frame to hold the camera in repeatable positions so you
can make exposures from several consistent views.
Check out the 3-D reconstruction software. There are several
outfits on the web. I talked to all of them about 12-18 months
ago, as I thought this could be the next turnkey business deal,
like the computer picture on a T-shirt setups that were popular
about 15 years ago. the bad news is, their software does great
for a house, a post office or something like that, but has a horrible
time with a face, and can't do the hair at all. One of the companies
has a beautiful face 3-d model on their web site, and I was all excited.
So, I asked, how did they do that. Fortunately, they were very honest,
and said that a lady who 'massaged' 3-D models for a living cam in
and did about *** 8 hours *** of hand massaging to identify the
identical point in each of up to 8 photos so the software could
do the math and make a rough 3-D model, which she then cleaned
up. Worth it for a good picture on the web site, but not practical
for your purposes. Oh, yeah, the back of the head, they just faked it,
as the software was hopelessly unable to cope with a scene that had
practically no major features at all.
Now, converting the 3-D model to toolpath is still the same.
The machining is also the same.

Still not cheap, by anyone's standards!

Jon