how to make punches and dies....

[DoctorX]

I posted this on another thread but wanted to send this separately in case anyone misses it.


First....get a Whitney 91 punch, it is a 10 ton (TEN ton) hand operated punch press, bench mounted. Cuts through 3/32" forbon like a hot knife through butter. They weigh about 90 pounds and don't cost too much when you can find them. I bought 2 for $100.00 each.

Cut forbon into strips the short width of the finished piece (about .98" or whatever it is).

Create trimming and parting dies to punch the shape out of the strip. The width of the strip takes care of two sides of the finished piece. You have to punch only the other two sides.

In all cases, the sides of the forbon pieces (strat and tele top and bottom) are symmetrical.

You create the dies out of sections of tool steel bolted together. The punch portions you create out of tool steel mounted in a carrier.

Since the sides are symmetrical, you profile a piece of tool steel about 12 - 18 inches long, and cut the punch pieces (think slices of bread) as you need them, harden and grind to finished shape, and mount in a carrier.

You create the punch with a degree of "shear" so the full 10 tons is concentrated on a portion of the punch as it travels down through the material...NOT on the whole blank at the same time. Think large paper cutter.

You can punch 1/4 in holes in thick forbon with a good hole puncher. It isn't dead easy but I've done it to determine what kind of effort / power is needed. Use the same principles to design a multiple hole puncher using a Whitney 91 punch for power.

What you have to figure out is how to exactly shape and grind the punch and die to provide the proper clearance to produce the blank to the size you want it.

Obtain and figure out how to use a surface grinder. Without it your efforts may well be futile. With it, you can make just about anything you will need, punch, die and mold-wise.

I have given you a boat load of ideas. The rest you will have to figure out. No more hints. This is the basis of why the punches and dies cost so much to have made for each part you need to make. They are built to last and be maintained by a tool and die maker.

I have mentioned sources of information on these forums before.

DoctorX

[Phil m]

Interesting, gotnee pics by any chance for the mechanically engineered challenged?

A close up of the two parts of the die, the press and the resulting piece would be a VERY big help for me to understand this better.

[Spence]

1 punch.jpg

There are other alternatives out there. It's the general spec that's important.

It's no picnic making shears, punches and dies but it is worth it.

[David Schwab]

Here they are punching out parts at Bill Lawrence


"Here, Ross is stamping out coilform parts."

[Phil m]

It's just too bad you can't really see what the dies look like. That would give a better idea of what we have to build/machine exactly to use a press.

[David King]

If you've see a paper punch for 3 ring binders you'll have some idea.
The parts have to be massive and rigid and perfectly aligned. You also need a way to clear the debris (chads?) out of the female section so it doesn't get clogged up.

[NightWinder]

That info is great. Fuel for the mind.

[DoctorX]

This is the book that explains the design principles and methods for die design. I use this book (among others) daily.

http://www.industrialpress.com/en/Bo...3/Default.aspx

It is called "Die Design Fundamentals"

The picture from Bill Lawrence Pickups in an earlier reply is showing an arbor press in action, with a small die shoe at its base. This can also work, and a good sized arbor press is about $160.00 new from Victor Machinery among others. The key here is rigidity and weight. The press and die(s) must be rigidly and securely mounted to each other, bench, floor, etc for good results. No half measures allowed. The bigger and heavier, the better -- within reason, naturally.

DoctorX

[David King]

Here's a Whitney #91 on ebay
http://cgi.ebay.com/Whitney-Heavy-Du...QQcmdZViewItem

Buy it now: $199
Ship it tomorrow: way too much...

[Joe Gwinn]

Originally Posted by David King

Here's a Whitney #91 on ebay
http://cgi.ebay.com/Whitney-Heavy-Du...QQcmdZViewItem

One thing that bothers me is the perfectly uniform coat of paint all over everything, never mind if that part of the item should be painted. This kind of paint job often bespeaks an attempt to cover a problem up, and sometimes only ignorance. Sometimes the problem is rust, sometimes it's evidence of a crack or repaired crack in the frame.

The note about the crooked handle is also a worry - someone overstressed the handle, and perhaps the frame. If the frame is bent or crooked, the punch will be essentially useless.

I'd give this one a pass. Such presses are not exactly rare.

Buy it now: $199
Ship it tomorrow: way too much...

It will weigh almost two hundred pounds when crated. Between crating and shipping, it could be an added $200, raising the total cost to $400. Unless one lives in a machine-poor area of the country, it should be possible to do better. I'd check local used-machinery dealers, and craigslist.

[DoctorX]

The Whitney 91 punch you see on ebay if you follow the link posted earlier is the larger version with the longer depth to the rear of the press. The ones I bought have a shallower depth (about 4 - 5 inches give or take). You do not need the version you see on e-bay, but the smaller one. The frame is still 2.5 inches thick regardless.

[corduroyew]

I've been looking around trying to find something like this in the UK. Can one of you UK guys tell me what kew words to use in my searches?

[DoctorX]

www.americanwhitney.com

815-965-1792

[Sock Puppet]

Originally Posted by corduroyew

I've been looking around trying to find something like this in the UK. Can one of you UK guys tell me what kew words to use in my searches?

Try arbour or arbor press in ebay.

S.

[Spence]

After a bit of trawling I've found something in the UK.

17.jpg

This company does quite a few models

http://www.hartleige.com/bench-punches.htm

No idea of prices yet.

[Joe Gwinn]

Looks pretty nice.

One thing I would add - if the intent is to punch stainless steel, the machine needs to be about twice as strong as for an equivalent thickness of mild steel. Stainless steel is far stronger than mild steel, and far more gummy.

[corduroyew]

So how many tons do you guys think we NEED to punch forbon anyway? Do you have to have a large 10 ton punch? or could someone survive with a 2 or 3 ton puch while while they wait for a good deal on a larger punch?

[Spence]

Hell no. You could use a 1/2 tonne punch without any trouble. Not sure how we got talking about punching holes in Stainless steel. That website link shows a range of punches with charts available for tonnage calculations etc.

[NightWinder]

Originally Posted by Sock Puppet

Try arbour or arbor press in ebay.

S.

Hell No! That Whitney's a bad MotherFuc@#!

[Joe Gwinn]

Originally Posted by Spence

Hell no. You could use a 1/2 tonne punch without any trouble. Not sure how we got talking about punching holes in Stainless steel. That website link shows a range of punches with charts available for tonnage calculations etc.

I'm guessing that people are thinking baseplates and covers as well.

[wilser]

hi guys,
What about this little fella? would it be useful for punching out the magnet holes?

http://www.americanwhitney.com/45HandOperatedPunch.asp

[David King]

Wilser it can punch a hole in 1/4" steel so it should certainly handle forbon but how would you line up your holes accurately? Wouldn't a $39 drill press from harbor freight be a lot more precise?

[wilser]

Originally Posted by David King

Wilser it can punch a hole in 1/4" steel so it should certainly handle forbon but how would you line up your holes accurately? Wouldn't a $39 drill press from harbor freight be a lot more precise?

well I have a $120 craftsman drill press and I'm guessing the same problems I would have there with alignment I would also have here, no?

[Joe Gwinn]

Originally Posted by wilser

well I have a $120 craftsman drill press and I'm guessing the same problems I would have there with alignment I would also have here, no?

Yes and no. You will need to make some kind of drill jig to get things in line and properly spaced in either case. The Whitney punches have little points on them, and these points are intended to be used in locator holes, so one can use a jig to drill a line of 1/16 holes, and then use the punch to make the holes.

Or, you can use a jig to drill full-size holes.

I suspect that the punched holes are cleaner.

[corduroyew]

The problem with a cheap drill press is that the table isn't rigid enough. I have a harbor freight drill press and the table flexis down when I drill through the forbon. That makes the holes wonder about .25mm to either side of the bobbin. If the hole is only .25mm off center thats bad, but not the end of the world. If one magnet is .25mm in one direction and the other is .25mm in the other direction, then thats not ok.

[David Schwab]

Originally Posted by corduroyew

The problem with a cheap drill press is that the table isn't rigid enough. I have a harbor freight drill press and the table flexis down when I drill through the forbon. That makes the holes wonder about .25mm to either side of the bobbin. If the hole is only .25mm off center thats bad, but not the end of the world. If one magnet is .25mm in one direction and the other is .25mm in the other direction, then thats not ok.

You sure everything is tightened up? I have pretty much the same $37 drill press, except mine came from Homier, and mine doesn't flex at all. You shouldn't have to press down that hard anyway... let the drill do the work. Your bits might be dull.

Drill bits and chucks can flex a little. It's good to make a drill guide. I did this for drilling the six holes in the back of my Tele style guitar for the string ferrules. The other important thing is to use brad point bits.