🚀 go-pugleaf

In article <zben-210892220341@zben-mac-ii.umd.edu> zben@ni.umd.edu (Charles B. Cranston) writes:
>In article <1992Aug21.012025.13775@pony.Ingres.COM>,
>bonobo@Ingres.COM (David Victor) wrote:
> 
>> I'm trying to make a nice-looking aluminum front panel for a project,
>> and I'd like to be able to use rectangular switches, possibly other
>> squared-off displays, etc.  How do you cut a perfectly-squared-off hole
>> in an aluminum panel?  Is there some home-brew method I'm not aware of?
>
>The best way, of course, is to use a chassis punch.  You drill a hole
>(within the final desired rectangle, of course) and thread through the
>screw.  Then the screw tightens the knife part of the punch into the
>die part of the punch, and cuts the hole cleanly.  The downside is the
>expense of the punch itself.

This way works fine, of course.  If you have a lot of holes, though (especially
if they're sizes that you don't have a punch for!), a milling machine is
the standard way to cut rectangular holes.  (The edges of the rectangle have
a radius the same as whatever mill bit you used, of course, so you need to
use a square file afterwards.  But filing is easy on aluminum.)  If you
have access to a reasonably well equipped machine shop, you'll also be able
to cut parts of circle in probably any size you'd like (crescents, circles
with square protrusions, etc.)

>
>The next cheapest way is to use a "nibbling tool", a hand-operated tool
>that "nibbles" rectangular chunks (about 1/4" by 1/10") each time you
>actuate the handle.  You drill a hole, within the final rectangle, just
>big enough to get the nibbler's head in.  Then you nibble out to "near"
>the rectangles boundary, and finish up with a metal file (though
>actually after a little practice you can get very precise at the border
>by "nibbling" less than a full "bite").  This is especially effective
>if you have a bezel to mount around the hole to hide the edges.

Yeah, I've nibbled plenty of holes myself too.  Too bad the cheap nibblers
won't do 1/8" front panels. :-( (Not that you _have_ to use 1/8" panels...
that's just what we use around here.)

>I should probably invest in a DB-25 chassis punch, since it is really
>tedious making that odd shape with a nibbler...

I wish I could afford one!  They're about $250, as I recall.  (And even if
I make 50 punches with it in the next 5 years, that's still $5/punch!)

						---Joel Kolstad