I am in the process of selecting a cad program and milling
equipment, do any of you out there have any suggestions and
experience with these programs?
Considering the products you wish to create, my advice is go with
ModelMaster. Mike and Co. are great people, ArtCam JewelSmith is a
GREAT product and improving with each release, and the MM milling
machine produces great parts with dead smooth surfaces.
I am going to be designing bracelet modules, earrings, and
necklace modules as well. Not going to do much with rings right
now. I need to be able to shell out these pieces and have designs
on the insides of these parts. I need to be able to easily scale
these pieces so that I can get step downed versions of the exact
same piece so that my necklaces will have a graduated effect. Also,
I wish to carve very specific designs [mostly geometric] on the
surfaces of these pieces. I know that cad is accurate to about 12
or so decimal places, I need to have a mill that can cut to about 3
or 4 decimal places with complete accuracy. Can anyone help me?
You state you need a mill than can cut to 3 or 4 decimal places with
complete accuracy. I’m assuming your referring to thousands or 1/10
thousands of an inch. .001" equals .0254 mm. The MM mills cuts
accurately to .01 mm, so you’re in the ballpark there. There are
other factors to consider though. The tool you’re cutting with needs
to be accurately measured. If you’ll be cutting very fine details,
you’ll most likely be using an engraving cutter, either a split
cutter or a 3 sided pyramidal cutter. You must have the angles and
cutting tips measured exactly, and tested. Milling to tolerances this
tight is no easy feat. If you’re using 4 axis, then you’ve got some
additional slop that is unavoidable. What you may find is that in
real world milling, your needs are not a great as you imagine them to
be unless you’re producing multi-part hard metal molds the parts of
which must fit within .001" (more difficult than you can imagine).
Rhino cannot currently produce shells per se, but may be able in the
next release. To produce a shell in Rhino is presently quite labor
intensive, but it can be done manually. I’m working on a comparison
between Rhino and ArtCam JewelSmith, but it’s going to be some time
before it is finished because I can only work on it in my spare time.
I’ll post it here when finished. It may help someone like yourself.
At my ArtCam training I was shown how to produce shelled objects. I
believe this is a somewhat new feature and is a bit tricky. I haven’t
seen the new release of ArtCam yet (I use JewelSmith and the new
release is not available yet), but I believe it is being improved to
make it easier. A program like SolidWorks (history based parametric
modeler) does an exceptional job of shelling but lacks most of the
features that ArtCam offers.
Please be aware that not all you parts may be possible with a
milling machine, so occasionally you may need to send a part out to a
service bureau that uses either the type of machine that Gesswein
sells (PatternMaster or even better, RapidToolMaker) or the new
Perfactory. In the case of the Perfactory, a rubber mold needs to be
made as the photopolymer it uses leaves an ash residue. I don’t
advise buying such an expensive machine (Perfactory is $49K) unless
you are going to keep it quite busy. I can make recommendations re:
service bureaus should that need arise.
I am leaning towards Modelmaster, but am not sure if their mill
has the capabilities to back carve these designs. I don't need to
have undercuts, but in some respects the insides of these parts
will be more complex than the outside surfaces or shapes, Also, I
need to be able to mill hidden tight fitting hinges which may need
to be milled as separate parts and then lasered together.
You can mill undercuts in a couple of different ways should the need
arise. If you don’t need undercuts, I don’t see why you don’t think
backsides can be milled. I produce complex pendants with accurate
details in the hollow of the back quite easily, just by flipping the
part 180 degrees and milling the back Regarding hinges, all you need
do is mill the concavity for tubing to fit into, assemble tube
sections onto the rivet, and solder or laser weld the whole assembly
as appropriate.
All of this is making me a little nervous, because it isn't my
money to spend, so I need to get the right equipment the 1st time!!
I look forward to getting all of your feed back, I hope to buy
this equipment no later that mid June so that I can get product out
for the Holiday season. Also, have any of you taken the classes
that these different programs offer? What did you think of the
progress you made? And has anyone gone back for tutorials and
extra workshops?
I think you should have no problem getting product in time for the
holiday season.
I have taken the ArtCam training and it’s very good. You make 5
different pieces (milled waxes) in two days. Tech support is
immediately available when required and there is a growing ArtCam
community available to help as well.
To be fair, you may find that your modeling suite may eventually
include several programs. In my case, I use Rhino and
ArtCam/JewelSmith, and occasionally LightWave (LightWave has some
modeling capabilities that neither other program has). I usually mill
my creations, but use RP service bureaus up to several times a month.
I also spend quite a few hours at the bench hand carving waxes,
fabricating, etc, whatever is required to produce what I have in
mind.
I hope the above helps a little.
Jeffrey Everett