|
When prospective clients ask if we offer
rapid prototyping, and we say "YES", it's automatically assumed
that we have a stereolithography machine in the back (we do have three FDM
machines for for demonstration models). For an appearance model, stereolithography
can be a reasonable choice, but if you want a part machined out of actual
engineering materials, one of our multi-axis CNC machining centers (Hurco
article here), the AbrasiveJet,
or the CNC lathe are what
you'll need.
The Fadal vertical machining center is a
very accurate, very fast tool. It’s big enough to mill an engine block,
and it is capable of 0.0001” accuracy. That’s not a misprint: one ten
thousandth of an inch! A human hair is 0.003". The vertical mill
holds 21 tools, can engrave the head of a pin, and can produce a
satin-smooth machined finish.
Mark Mossberg, our CAD/CAM specialist
(and a Mechanical Designer), is the person at Omnica who’s primarily
responsible for the operation of the Fadal. His nine-year anniversary with
Omnica is coming up. He worked the previous ten years sculpting prototype
parts for ALPS Manufacturing in Garden Grove. He has the knowledge, quick
answers, and self assurance of a person who has been around machine tools
for a long time. Omniview has some questions for Mark. His answers will
interest you.
OMNIview: Can
you tell us why this machine is particularly suited for rapid prototyping?
 Mark:
There are a couple of reasons. First, just because you buy the tool doesn’t
make you a machinist or a rapid prototyper. There are really three things
necessary to make rapid prototyping with the Fadal work; the operator, the
machine and the software. We have everything here you’d need to do rapid
prototyping and short production runs. With SolidWorks™, or I can take
an IGES file and read it directly into MasterCAM (the cutting program); it
goes in perfectly. I put the part in position and write my tool paths. The
real benefit of MasterCAM is that it’s 10 times faster than writing the
machine program code by hand. The cutting program does all the cutter
compensation and the math and geometry, but the program doesn’t make
decisions for you. I still have to choose the right cutting tools and
path, and figure out how to hold the part so there’s still a lot of art
involved.
OMNIview: Can’t
someone just hire a machine shop to do this kind of work?
Mark: No. The dividing line in this
business is doing the 3D machining. Most machine shops won’t touch 3D
work, they’re scared of it. Even if they have a machining center they
don’t know how to do the organic shapes. They make machine parts. There
are a lot of 3 and 4-axis machines around, but when it comes to doing
something like the swoopy wrist support you’ve seen on ergonomic
keyboards, it’s hard to find someone to do it. I’ve done a lot of mold
machining, and I can tell you that it’s the mold shops that do the 3D
work. Machine shops think it’s black magic.
OMNIview: What
kind of jobs fit best with the prototyping and pre-production services we
offer?
Mark: We can do the organic shapes,
but another good fit is for the customer who wants a short production run
of really accurate parts. I mean real accurate; where you can’t tell the
difference between the first part and the last one. With this machine we
can do complex, multiple tool, hands-off programming. It minimizes most
operator errors. You don’t pick up the wrong tool, put it into the
machine and drill a hole in the table. If you have multiple parts or
mirror-image parts you’re going to get consistent accuracy. Also, if the
customer wants a smooth finish that requires hardly any post-production
handwork, I can run a pass with the 60,000 RPM air spindle.
OMNIview: 60,000
RPM! That’s almost as fast as a dental drill. So if you could figure how
to clamp my head in there —
Mark: Oh heck yes. Just
lay down on it.
OMNIview: —you
could probably program a root canal or cavity removal?
Mark: I could, but I sure wouldn’t
want to miss by much.
OMNIview: Mark.
Mark. I was just thinking out loud. . . I’ll pass for now.
|
