[sdiy] plexiglass panels for modular?

[KA4HJH]

I guess the use of acrylic or some other plastic is the "dream that won't
die". I myself have daydreamed about making cool looking front panels out
of the stuff for years.

At this point in this thread we've heard a number of horror stories and
caveats, all of which are well taken. The plastics we're talking about here
just simply don't behave like wood or metal. They don't "shave" the way
wood and metal do, they just sort of "chip". In some respects it's more
like working stone or glass, only not as hard and brittle.

I'm fortunate to have a plastic fabrication company near where I live, and
they gave me a very interesting tour of their facility a few years ago.
They have expensive carbide blades, specially re-ground drill bits to avoid
the cracking problem, and a variety of other neat tricks which they
graciously shared with me. This in itself was something of a
surprise--you'd think they'd keep their trade secrets just that--a secret.
They didn't mind telling me because, quite frankly, it was enough to
totally discourage most people from attempting to work with the stuff. They
obviously weren't worried about somebody like me becoming a competitor.

Now that I have a much better understanding of the practical problems
involved I'm not quite so eager to embark on my dream project but I haven't
given it up entirely. Suffice to say that if you're going to do it you need
to do some homework--or waste a lot of expensive material re-inventing the
wheel.

I did manage to build a small display case for some high voltage stuff I
have, and it was a total pain in the ass. There isn't a perfectly square
joint in it anywhere, and I was using a decent table saw with a new carbide
blade to cut it just like they told me to. Looks really cool when
everything is lit up, though. Most people would never notice--but I know it
isn't right.


Some practical advice that hasn't been mentioned already: don't even think
of trying to make something remotely decent unless you have a table saw and
a drill press. You can use the old "score and break" technique to cut it
down to size but that doesn't leave you with a cosmetically clean edge. And
the technique doesn't work once you get below a certain fairly large size.

Don't even think of using ordinary twist drill bits--you'll need something
more exotic and expensive like Forstner bits (worked for me) or brad points
as Jim mentioned (haven't tried that one).

Acrylic is really flexible--much more so than aluminum. You need a much
thicker piece to get the same stiffness. If you think 1/8" aluminum is a
bit flexy try some 3mm acrylic! You won't be pulling many 1/4 phone plugs
in and out of that stuff before getting annoyed with it, assuming it
doesn't break somewhere first. This is IMHO one of the most difficult
problems with using it for panels, assuming that you succeed in making
panels in the first place. You'd have to use a piece so thick that simply
mounting components becomes a serious problem.

Several people mentioned polycarbonate. Aside from smelling even weirder
than acrylic when it's machined it also scratches even easier (it's
actually softer than acrylic), which AFAIC makes it useless from a cosmetic
standpoint. It's great if you're making something bulletproof but that's
not what I have in mind. Might be better for making a road synth out of but
I doubt it would survive the rough handling.
-- 

Terry Bowman, KA4HJH
"The Mac Doctor"

"Damn, damn, damn, DAMN!"--Prof. Henry Higgins, "My Fair Lady"--or was it
one of Shaw's?