anyone use plexiglass faceplates?

[KA4HJH]

>I had an idea this morning, and I was wondering if anyone has tried something
>similar before.  I'd like to try using a plexiglass faceplate for my synth,
>and have the panels engraved at a local shop.  I was then planning on
>painting the inside of the face black, and backing them with a thin piece of
>aluminum for shielding/grounding.

Been thinking about this for a long time. I started to get so many 
good visual ideas that I got up off my duff after almost twenty years 
and started building. Kinda stalled at the moment; maybe this is just 
what I needed to get going again. I forget how exciting this idea was 
(as some of you know this happens to me).


>My main goal is to edge-light the panels so they glow a little, and the
>engraved lettering will glow brightly.

Use a cold cathode lamp, like a laptop. There are very small ones 
routinely available now. Rubbing something fluorescent into the 
grooves might make it brighter, but you still might have a problem in 
broad daylight.

Another variation would be to paint the back with something 
translucent or even leave it clear in places--keep it black around 
the dials and other labelling--so you can see the bicolor LED's in 
the LFO's glowing. This is a good reason to put one in every module! 
Better yet, you could put an LED bargraph in there and watching the 
light move back and forth. Don't forget to use some blue LED's.

If you don't want to fool with the edge lighting (it uses a switching 
PS so that's a source of trouble) there's still a lot of cool things 
you could do with backlighting with ordinary LED's, but you won't be 
able to cover the entire panel unless you use a _lot_ of LED's. Just 
stick some behind every spot with some engraving.


>Think it'll work?  Any durability or scratching problems with plexi?  I plan
>to mount a rigid enclosure behind the faceplate, so panel flexing shouldn't
>be a problem.

Scratching is always a problem with acrylics. You can spray a coat of 
Urethane over it.

My own scheme is to have aluminum panels (black, of course) on either 
side for mounting the jacks (inputs on the left, outputs on the 
right--we'll see how long that lasts). Now there won't be hardly any 
flexing of the  acrylic panel at all. At the worst I may have to 
epoxy some aluminum angle on the back. This means that I have to 
unscrew three panels instead of one to remove it but I'll live with 
it.

BTW, If you're doing it yourself you need a table saw and a good 
carbide blade. Drilling is a problem because ordinary twist drills 
tend to cause cracks. They make special (more expensive) bits for 
this; I've have pretty good luck with Forstner bits.

Terry Bowman, KA4HJH
"The Mac Doctor"

ICQ: 45652354