Hi John!

On Sun, 6 Apr 2003, John Sanderson wrote:

> >Ok, I've found some options for buttons, now my problem is punching out the
> >square areas for the buttons (and LCD).

> The `right' answer depends entirely on the qty. of panels you want. If
> you are making any no. greater than your fingers and toes then find a
> local N.C. punching house, give them a drawing and get them to do it.
> It's quite cheap per unit.
>
> If you want a one-off or just a couple, ...mmm... there ain't any nice
> choices. I've used a bench mounted manual punching rig for years & it
> has rectangular + round punch & die sets.  Very time consuming to set
> up, but it's the only way I've got for one-of-a-kinds.

'Cheap per unit' and 'time consuming to set up' are key phrases there. At
an outside house the per unit might be $0.50, but the job setup charge is
$100. :/ So as you said depends on qty.

> I'm about to procure a small combination lathe + mill so that I can do
> all the little irritating machining jobs myself, killing the induced
> delays caused when I have to rely on outside shops to turn round `quick'
> tasks. I fancy that it might also be practical to use the mill for
> knocking out the oddball panels too. Has anyone tried this?  i.e. making
> rectangular holes (er.. with radiused corners) in thin steel plate using
> a mill?

I've milled sheet metal aluminum. There's (or at least was) a company that
made beautiful 'show quality' cases, *very* expensive, 1/8" aluminum,
pebble paint texture finish, walnut end panels and such. They looked great
but were a *royal* PITA to work with to keep them still looking show
quality after a few days in a machine shop. LOL! They took some damage
anyway but essentially invisible, hidden by the pebble finish.

Can't nibble that thick stuff and it would smash the paint around the
edges anyway. Easy to drill *but* hard to large quantities of filing to
shape and not muck up the paint at the hole edges. Milled at a nice high
speed rotary but slow feed. Made a clean, smooth, square edge cut that
required no further finish work. IIRC didn't have to do much if any square
corners.

In your case the radiused corners would be fairly trivial to finish with a
square file, all the other flat edges are already straight and square.
It's a matter of clamping it down so it can't slide, and backing with some
wood because of course you don't want to cut the table. And maybe paper
between any existing finish and wood to avoid marring.

Have done a lot of whittling on a band saw and 'freehand milling' on drill
presses too. Almost any tool can be adapted to something else as required
by task. :)

Have a :) day!

jb

--
jim barchuk
jb@jbarchuk.com

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