Punch manufacturers?

Does anyone have a good source to make a custom die for cutting 20 gage copper? It's intended to be used with a hand punch, and the pattern would fit inside a 1.5 inch circle.

At this time, I have neither hand punch or any dies, just a shape I need lots of out of 20 gage copper, and a dream that there must be an easier way! Any ideas??

Also, I could be interested in a plasma or water jet cutting service, perhaps that'd be cheaper, for 200-500 pieces?

Thanks!

Whose hand punch? I get my punches from Roper but then again my punch is a Roper.

Plasma cuts in copper tends to leave a knarly burr on the back. Not a show-stopper but something to be aware of. The problem may be in finding someone who wants to cut non-ferrous. Also those with CNC will want to handle stock in sheets while copper comes in rolls.

starbolin

Cleveland Punch, among many others, makes custom punches- but no custom punch is cheap- I know at least 15 years ago, I was quoted $500 for a 1/2" diameter 5 pointed star punch and die set for my Whitney bench punch- and I would guess prices have gone up since then.
http://www.clevelandpunch.com/

So if your design is at all complicated, and its 1 1/2" in diameter, you could easily be looking at a grand or more in tooling costs.
Even in 20 gage copper, the tonnage required could be a fair amount, too.
Punch tonnage is calculated based on perimeter length- and most punches are sized for round holes, which, of course, have the minimum perimeter of any shape.

Here is a link to a tonnage chart-
http://www.roperwhitney.com/tech/chart1.cfm

In mild steel, you would need a minimum of a 5 ton punch, depending on the shape. In copper, you can derate some, but its always better to have more tool rather than less.

I am guessing, without seeing the shape, you are talking 5 ton bench punch. Not a traditional "hand" punch. You need more mass, and rigidity, to hold any shaped punch, as anything but round must be held in exact alignment, elsewise the punch hits the die, and there goes your thousand dollar custom tooling.

Another problem is die size- most small punches, bench and hand, wont do a hole bigger than about 9/16", as the die must be much bigger than the hole punched. You gotta get into a bigger, or more specialised, punch, to punch a 1 1/2" hole.

I would be looking at a punch like this-
http://www.americanwhitney.com/91BenchPress.asp
As it will go up to 2" diameter.

I would definitely get quotes on waterjet and possibly laser cutting.
Prices vary regionally- some places are lousy with waterjet shops, and there is a lot of competition, other places the lone guy can charge what he wants.
Pricing is based on perimeter length and cut quality- if they run faster, its cheaper, with worse edge quality- which shouldnt matter on 20 gage, but can be a factor on 1" plate.

In Seattle, there are quite a few waterjet and laser shops. I am up in the Skagit, and I use local guys up here, but haul out the yellow pages- I have used a big shop over in Bellevue, down by Coal Creek, that was good, and I know there are some in the south end as well.
Several in Lynnwood and Everett, too.

Intial cost of waterjet would be much cheaper- a couple of hours of programming time, max, depending on your design- if its simple, even less.
Whereas punching is more upfront. Especially in Seattle, where the chances of finding a used punch are pretty much nil.

Here is what I came up with to do heavier punching at home. I'm using a 40 shop press, just a standard issue, normally used for pressing off bearings and such.
Ries: You can get around the alignment issue using what I did. You have to make up a self contained die set. If you have access to an EDM wire machine you can easily do it. Wire cut the desired shape, then backtrim(1-3 degrees plenty) the wire cut a slot for where you feed the material through.. I'm punching .075 thick stainless in a L shape.


I grind shape punches for a living so I have that advantage I guess. Most presses have a 1 inch arbor hole so if you get a 1 inch shank with a bigger punching surface, it can be done. We refer to them as "point larger than shank" I can dig up finished part pics if you wish to see it. Kevin

die set is on the lower left with the punch just above. drill jig on the lower right with just a little of the roll bender show above it. On the die set you can barely make out the slit on the side where material is fed through. I was having problems with punch breaking from release shock but I think I solved that by lowering the rockwell on it. Punch 200 pieces now with no breakage with that punch. Here are some finished pieces:

Forget laserjet, you can't cut brass or copper with a laser.

Best way to do this at home on the cheap is with a 12 ton shop press available inexpensively from HF, and shop-made tooling.

Grant Erwin
Kirkland, Washington

check out the nameplate industry... I agree with Ries...24ga is kind of heavy material and will require some decent tonnage

http://www.impactlabel.com/aluminum-nameplates-aluminum-labels-dataplates.htm

fwiw 20 ga copper translates to 24oz. per sq foot. For stamping/die cutting I would guess you will want to specify 24oz. CRC (cold rolled copper)vs. half hard or dead soft temper, alloy #110, when you order your sheet stock.

Metalliferous sells the 1.5" flat copper circle blanks for around $40 per gross, but it's 18ga.

http://www.metalliferous.com/images/BMC7180.pdf

Thanks for the great suggestions!

Unfortunately, I've no edm machine available to me, or the captive die thing would be perfect! I suppose I could pay big bucks to get one made, but for what I'm doing it's not worth it.

Thanks again.