SSR-III Front Panel
Sheet metal layout
The 1/8" thick aluminum front panel is a standard 3 Rack Units (RU) high (5 1/4" x 19").
I covered it with (peel and stick) paper and transposed the computer graphics layout, which was
designed 1/2-size to fit on print paper, as can be seen in the photo.
Now is a good time to make sure there are no interference problems with the panel components.
Since the panel graphics program showed only the front layout and the basic cosmetics, a double
check of the component clearances on the rear of the panel is definitely in order prior to milling and
drilling. Note the dashed lined below the meters. These represent the actual panel space occupied by
the meters. That's a good thing to know before trying to mount a pot or switch in a hole that's been
covered my a meter movement. What isn't apparent here is that I've made some dimensional
adjustments in order to allow everything to fit.
When my finger heals a bit more, from a recent operation, I'll clamp this plate in the milling machine
and try not to screw-up. One more note is in order. Before I had a miller, I used to drill these things by
hand ... that's not a big deal. Things like the meter cutouts are a bit more trouble but really not that
bad - you just drill some holes in the corners of each rectangular cutout, insert the jig saw blade and
cut away. I always cut "small" so that I could finish up with a file and have a perfect fit for the meters,
or whatever it was that required something other than a round hole. Tip: a good aluminum-cutting file
and a decent vise are a must.