There are very good reasons for exporting a cam friendly file from
a cad program. Far fewer chances of shooting your self in the foot
or both. Converters are weird and tend to do strange things.
This is very true Jeff. However I like my modeling package
(Lightwave), because it is like using plasticene, it has a decent
rendering engine, lighting is good, radiosity etc. etc. etc. blah
blah blah.
Converting the models (.lwo) to an.stl file does require a plugin,
also another program that makes that.stl file water tight, which is
necessary if you want to grow a wax model.
I could have made my life a lot easier by using Rhino which has a
native export to.stl, so no repair of the model is needed. It’s a
matter of what we like to play with.
I will have the opportunity to own a copy of Rhino + plus a nice
Jewellery add on, as it is part of my course. This is nice because I
wont have to give up the modeling tool I like, because Rhino can
import .lwo files
You need to learn what you are talking about before you jump into
the middle of it. From your own statement:
I can't say anything about CAM, because I am not using it, but I do
have some knowledge of CAD.
For the majority of goldsmiths/jewelers CAD is inextricably linked
to CAM as the vast majority of users are looking to directly mill or
grow a pattern to be cast into a piece of jewelry. By your own
repeated admission you don’t work with cast items so at best this is
an area where you have no experience and no expertise.
Believe me when I say that his demonstrated depth of knowledge with
CAD/CAM is vast. Certainly greater than a mile or two from Maya.
The Binnion part, yep. To take this thread a different direction with
the Maya part. Not exactly fantasy but wishfullness, I guess. I have
a friend who was with Cartier - now he’s at Saks (sales). He was
griping that Cartier’s inventory all looks like parts off of a car,
nowadays. I believe that part of people’s distaste for much CNC
jewelry is just that - mechanical, straight lines or at least ~too~
much perfection in the wrong places. I brought Maya up as a thought
about Autodesk’s arsenal of products, and it is a bad choice for
jewelry modeling mostly because 80% of the program is things other
than modeling. It IS a good tool for modeling Buzz Lightyear,
though, because it’s less constricted than many true CAD programs
are. I.E, it’s easy just to push and pull things until they are
“right”. Another problem, just BTW, is that there’s no measurements
in Maya. There’s a “unit” but it’s just “a unit”, not an inch or a
millimeter - maybe that’s changed, now.
Zbrush holds the same potential - more artistically based, less
engineering and strict geometry. Easy to make “smurfy” things…
Or as we used to say, “It’s like, organic man”. But, neither program
is especially CNC friendly. Certainly Zbrush doesn’t export STL files
and it’s also a little TOO artistic. It can be difficult to get a
circle for a ring of the right size, for instance. Just rambling a
bit… Many would say that CNC jewelry LOOKS engineered, and it is
difficult to draft a good leaf on a computer, it’s true. A blending
of it all that was CNC friendly would be a fine thing.
Rhino, by the way, is a surface modeling program, not a solids
modeler. While it can construct enclosed surfaces which it can
internally treat as solids in certain circumstances, if, for
instance, you subtract a cylinder from a cube, you will get a
hollow cube with two holes in it,
To set the record straight, Rhino is in fact a solid modeler, you
can create a cube, and then subtract a cylinder/s and get a solid.
Rhino allows one to create curves, surfaces, polysurfaces and solids.
You can read more about it’s capabilities at Rhino3d.com. Many of the
new CAM programs (Esprit, Mastercam, Surfcam) require solids for
feature analysis and auto recognition of features such as drill holes
and pockets. I create these required solids in Rhino. Email me direct
and I’d be happy to demonstrate the above example. Hope this helps,
Phil The image below is a screenshot from Mastercam X5 with a solid
made in Rhino
Zbrush holds the same potential - more artistically based, less
engineering and strict geometry. Easy to make "smurfy"
things...... Or as we used to say, "It's like, organic man". But,
neither program is especially CNC friendly. Certainly Zbrush
doesn't export STL files and it's also a little TOO artistic.
Zbrush most certainly exports STL files and has two plugins
(Decimation Master and 3DPrint Exporter) that assist in exporting
files ready to run into RP machines or CAM packages. It has some
drawbacks certainly and I would not to only have Zbrush in my tool
box but it is a great tool for “organic” modeling.
For the majority of goldsmiths/jewelers CAD is inextricably linked
to CAM as the vast majority of users are looking to directly mill
or grow a pattern to be cast into a piece of jewelry. By your own
repeated admission you don't work with cast items so at best this
is an area where you have no experience and no expertise.
I love the argument about majority. That is what we call “Ad
Populum” fallacy, aka safety in numbers. You are going to have to do
better than that.
But I want to concentrate on your last pearl of wisdom, where you are
implying that because I do not work with cast items, than I cannot
possibly know anything about CAD. Now, now - aren’t we been
presumptuous. So, let me present my credentials.
I have degrees in Monumental Arts, Computer Science, Mathematics,
and Ergonomics. In addition to my goldsmithing career, I work 3 days
a week for very large international bank, where I am an Assistant
Vice President with IT Infrastructure division. I coded my first CAD
program 30 years ago, in assembler, and I can still read unformatted
mainframe dump. My hobbies include talking to CAD experts, and
asking them to explain things to me. Quite entertaining I must say.
So, since you know a bit more about me, do I have your permission to
talk about CAD ?
Is there any reason to prefer G98 to G99 when G81 through a jig? Is
there any reason to prefer to have the tool number and M6 on
different lines when using a low number FANUC controller? With
Heidenhain controllers, do the N numbers matter? Does the trailing
program ID number have any effect on program execution? When surface
milling, is it better to mill straight to a corner, then switch to
the next axis at a hard 90D corner, or to call a G2? If so, what
radius should one use? Why?
Using G40, is it possible to peck tap?
What’s the difference between G73 and G83?
With a standard milling cutter, is there any reason to prefer M2
over M3? Or would G1 be more appropriate? Why?
When G83, is the Q length calculated based on the initial point, or
the R point?
In any of the standard drill cycles, why would you call P? Why call
G80?
Would you call G41 before or after a drill cycle? Would it matter?
Why?
Zbrush most certainly exports STL files and has two plugins
(Decimation Master and 3DPrint Exporter) that assist in exporting
files ready to run into RP machines or CAM packages. It has some
drawbacks certainly and I would not to only have Zbrush in my tool
box but it is a great tool for "organic" modeling.
That’s good to know - I pasted the whole quote because it’s good to
know. That’s new to me - the versiion I used some years ago didn’t
have any of that. It has evolved quickly.
I coded my first CAD program 30 years ago, in assembler, and I can
still read unformatted mainframe dump. My hobbies include talking
to CAD experts, and asking them to explain things to me
Guess you didn’t learn much… Jim Binnion is a CAD/CAM expert
and he’s been struggling to explain it to you without success, and
you recommended the ~worst possible~ program for making jewelry -
Autocad.
I love the argument about majority. That is what we call "Ad
Populum" fallacy, aka safety in numbers. You are going to have to
do better than that.
Actually there is no need to “do better than that” Since the use of
CAD by jewelers and goldsmiths is going to fall into two categories
either to create design drawings (technical or renderings) and or to
create models that are to be grown or milled. Since most of the use
for CAD in the trade is for the latter it is a statement of fact not
not an argument.
So, since you know a bit more about me, do I have your permission
to talk about CAD ?
You are as free as anyone on this list to stick your two cents worth
in to any conversation. However your stated credentials have little
to do with being a CAD modeler or CAD designer in the jewelry trade.
It is like saying you have a degree in aeronautical engineering and
had designed an airplane from wood and lacquered cloth back when you
were in school and then you went off to become a carpenter and now
you are trying to advise a fighter pilot how to fly.
