Re: [CAD_CAM_EDM_DRO] Re: Making a punch die?

Joseph wrote:

> Hi Alan,
>
> I'm actually more of an electronics guy. I decided to tinker with
> machining so that I can make a "finished product" when I work on my
> projects.
>
> Seeing as how these dies are about $60 for simple round punches to
> around $200-$300 for squares and connectors (DB, DIN, BNC), I figured
> that making "cheap" punches would be worthwhile. (Heck, almost pays
> for the CNC machine!) I plan on punching maybe 20 or so connector
> cutouts in a year, so I can't imagine spending $200+ for each die.
>
> I like the idea of CNC'ing the cutouts directly, and I was originally
> thinking of doing that; but I just liked the idea of making my own
> dies.

I have a Roper-Whitney 5-ton foot-powered punch press. I made a
commercial product about 10 years ago (before I had my CNC machine)
and would make up 10 cabinets at a time. I had a HECK of a time
keeping things aligned well enough that the connector and switch
holes were within 1/4" of where they were supposed to be, and that they
lined up enough so that people wouldn't think I built this stuff while I
was drunk! (The RS-232 connectors and the slot for the LED display
would really stick out like a sore thumb if they were more than 10 degrees
out of square, and I had trouble keeping within that tolerance!

I now have converted my Bridgeport to CNC, and practically NEVER
use the punch press. One time I needed a bunch of round blanks punched
out of a piece of brass, and another time I needed a large number of
1/2" holes punched in a grid pattern in a lawn mower air filter housing.
Those are the last 2 times U used the punch press. So, if you don't
care about precise hole location, and need a large number of the same
size holes, then the punches are pretty good. If you need it to line
up well, like with connectors soldered to a circuit board, you will
be disappointed with punching. (Commercial outfits make fancy
fixtures that hold the work in place for accurate hole location, but
it is a REAL pain to redo the fixture every time you change punches!

> Moreover, if this idea does work, I might donate some homemade dies
> to my alma mater. When I was a student, I was bummed at how shoddy
> my case looked.

Well, that sounds a bit better, but if you already have CNC, I think
you should stay with that. Then, you can have holes exactly where you
want them, and you can cut all the holes in one pass, with one tool!

Jon