Experience with CAD?

Jewelry Discussion
1

3D laser scanners do work, and can be used to produce computer models
from physical items.

I don’t think these things are very common, and think they’re quite
expensive.

This is one heRe: http://www.scantech.net/

There are quite a few manufacturers.

I’m just starting into CAD for jewelry. I’ve done 3D design in the
past with 3D Studio. My preference would be to design things in 3D
studio max, but I’m going to give JewelCAD a try (ordered the eval
from Gold).

Rhino 3D looks pretty good too.

  • darcy
2

Three dim. scanning has not yet arrived and it may never arrive. The
problem with scanning and cam is that the scanner makes pixels,
which are like dots on a t v set, and the cam machine needs vectors,
which are mathematical modals. When you work in 3d scanning you
receive a cloud and you have to choose your vectors from the cloud.
If you choose incorrectly, the cam machine will make your object
exactly as it was told and not necessarily as you wanted it. There
are machines for scanning and people out there that can use them, but
they are not all that easily to work with and the “experts” command
very fine fees for their skills. Also, if you scan property that is
someone else’s intellectual property, you have the problem with civil
and criminal liability. Your computer may end up as Exhibit 1 in a
trial over this issue. If your scanning things in the public arena,
why go to the expense of scanning? If you intend to make alterations
to the basic model, do you have the basic skills to successfully edit
a 3d model? Something which is not elementary in itself. Mike

3

Hello, Did you heard about FreeForm from Sensable?

This is a wonderfull digital sculptur application wich allow you to
import the cloud of points from a 3D scanner and correct it
interactively, modify the shape and export it to the cam.

It is not a $ free investment, but it is a superbe application to
generate stylish objects very rapidely and easely. For more infos:
visit www.sensable.com and why not
my site www.altair-consulting.com. Paul-Henri

4 
    Three dim. scanning has not yet arrived and it may never
arrive.  The problem with scanning  and cam is that the scanner
makes pixels, which are like dots on a t v set, and the cam machine
needs vectors, which are mathematical modals.  When you work in 3d
scanning you receive a cloud and you have to choose your vectors
from the cloud. If you choose incorrectly, the cam machine will
make your object exactly as it was told and not necessarily as you
wanted it.  There are machines for scanning and people out there
that can use them, but they are not all that easily to work with and
the "experts" command very fine fees for their skills.  Also, if you
scan property that is someone else's intellectual property, you have
the problem with civil and criminal liability.  Your computer may
end up as Exhibit 1 in a trial over this issue.  If your scanning
things in the public arena, why go to the expense of scanning? If
you intend to make alterations to the basic model, do you have the
basic skills to successfully edit a 3d model?  Something which is
not elementary in itself.  Mike

I’m not sure how accurate that is… first, no 3D scanners use
pixels, but may be using voxels (pixels are 2d “picture elements”…
voxels are 3d “volume elements”).

It’s not so hard to interpolate a voxel based description into a mesh
based description.

It doesn’t matter too much anyway, since the rapid prototyping
machines are voxel based as well. They take “slices” and render those.

Regardless of this, I think many of the products today will produce
3D meshes in a simple way.

Quoting from Minolta on their product:

http://www.minoltaeurope.com/press/stage_press24.html

“The combined SurfaceSuite PRO and VI-700 package will provide users
with a powerful solution for rapidly generating photorealistic 3D
content. The VI-700 quickly scans physical objects to create a 3D
wire frame mesh, and SurfaceSuite PRO provides a simple, yet powerful,
system for quickly and accurately applying textures to the 3D model.”

This was the first hit I got from a Google search. I don’t have any
personal experience using these things.

  • darcy
5

Hello, I have seen two model makers. One you are familiar with carves
out a model from a computer image. I think Reo Grande carries one.
The other I saw at the University of Illinois. They have a machine
that builds models from an image. It is supposedly better. It was
extremely expensive. They were using it to build molecles so
scientists could get a better idea of the entire structure. Lots of
computer power involved in this. Steve

6

Dear Darcy:

"Pixels v. voxels? " You are techinacally more correct than I was. I
may have over simplified to make a point. “Many products will
produce meshes in a simple way?” Every software vendor will state
this about its product. I have not found one that states our product
is difficult to use, full of bugs and is not compatible with all types
of hardware. Yet you will find out that this statement is true about
some products out on the market. I am not attempting to slam any
product, but I believe that you can take the sales representations
with a grain of salt. Until you have had the pleasent experience with
the error message design failed, abort, redefine, reroute,
investigate? and nothing you do workes and you have been at it for
hours, may be its only the dummy on the internet with these problems
or maybe everybody is overstating their claims. Mike

7

Mike, I have been working with CAD for almost three years. In that
time, I have been exposed to every CAD and CAM product that exists, it
seems. What you say is correct, absolutely. There is no CAD program
that works for all purposes, each needs its own workarounds. If you
are making illustrations/models from point clouds, sooner or later it
becomes problematic. We are at the edge of making this
affordable/utilitarian, but we are not there yet. And, yes, the
salespeople do have a tendency to overlook the shortcomings of their
product. It’s good to remember that just because we have a hammer,
everything does not become a nail. Having said that, as far as jewelry
design goes, the best I’ve seen is Rhino, all things considered
(price, ease of use, large user base willing to help/share, file
format capabilities). You might want to check them out at
www.rhino3d.com. I have no dog in the race, but I’m happy with the
product. Currently I am a beta tester for GemVision’s Matrix, a Rhino
based modeler designed expressly for jewelry which scripts lots of the
Rhino tools and lets me make unique images about ten to twenty times
faster than Rhino, and does things NO other modeler in the world does.
(Gemvision.com, ask for Kent, tell them Wayne Emery sent you…these
are some really nice folks). Again, I get no remuneration in any form
from anybody. Best to all,

Wayne Emery

8

Dear Wayne:

Thank you for your reply. I have experience using Autocad, Rhino,
Pro-e, plus about a have dozen other 2d Cad programs on both Mac and
PC platforms. I can also do some programing, such as make macros,
some simple de-bugging and make a few patches. Many people talk about
2 1/2d and 3d scanning to be one and the same. They are not. There
are several 2 1/2d modelers that use a flat bed scanner, that have
some usefulness in certain applications in jewelry. Clearly, they can
be used to make a lot of products. But they are far removed from
actual 3d scanners which use 3d clouds on a 3d field. You can
recieve very impressive demonstrations from the companies in this
field, but our firm had a 3d scanner, not a 2 1/2d, and had nothing
but problems. When we returned it, our best estimate that it would
take over 3000 hour of programing time at $150.00 per hour and no one
was sure that it would even work after the investment. Very hard to
justify! That does not mean that 3d Cad programs, when used in
traditional ways, cannot be used for a lot of our products or to make
a lot of our products better. We could get into a discussion about
the limits of programing on a 32 bit chip and the potential for true
3d scanning on the 128 bit applications, but we will exhaust the
good will of nearly every Orchidian. The 128 bit application is
probably ten years away. Our choices now are 2 1/2d with the limits
offered, very poor functioning true 3d scanning, makin 3d models
using nurbs geometry or extruing or revolving our designs to make 3d
objects. Mike

9

Hello Wayne, hello Mike. Well, if you talk about 3D scanner and you
would like to make a complete 3D apps from scratch, of course it will
cost a lot of time and money for a not easy result.

Let the pro do that and concentrate to make your mind about the
result you like to achieve, then make the good choice for you.( Money
wise and ROI).

To do a 3D scann, today the 3D clouds of points is the best way to
have good result, on the market, scanners accuracy goes from 10
microns to .1 mm (sorry it’s metrics!). Names are GOM, Minolta,
Rainbow.

Severall software (some heavy) are able to catch the 3D clouds of
points comming out of a 3D scanner (Alias Wavefront, FreeForm,
Geomagics, Delcam).

Of course, this is not the stuff you will find for free! but if you
compare the 3000x150$ from your exemple, but it is FAR LESS MONEY and
it works!

We recentely have done a reverse engineering process of an old object
from private museum.

The object was scanned with a Gom, scanned data cleaned with a
FreeForm Modeling, modification of the objects on FreeForm Modeling,
output on a Wax Rapid Prototyping by us, and casting of the object.
time was half a day scann, one day of modifications and cleaning, one
and half day to produce a 13 microns wax model.

I have to say that I do not care about informatics 32 bits, 128 bits,
etc. when I drive my car, I do not care about the power of the
electronic ignition also, but I drive a car (with attention). Before
having the right to drive a car I did pass a driving
license.(Important also for all the application software!)

So to make it short, do not say that the world is only 2 1/2 D!

Today there are good 3D tools on the market, and if you look around,
we are surrouned by a lot of 3D stuff! Paul-Henri

10

Dear Mike, There is a machine Modella with a 2 1/2 d scanner called
PICZA. It is good for many things, but cannot do 3d. Thjs machine
costs around $4000.

At the Vegas show, there was an experimental 3d camera displayed. The
gentleman, who was not present most of the time indicated a price of
app USD 20,000.

I hope you can get more info.

Regards,
Shishir