Some die help needed

[Farbmeister]

Hello all,

I am going to try and make a die set to punch out some loop type, flag style electrical connectors (1940's automobiles.. not available) for 8 to 16 guage wire and terminals of approx 3/16 1/4 inch.

Since this is a test run I am figuring on using A2 for the punch, and 'steel' (whatever is around) for the die (which will be case hardened - kasenite). Since the parts is a small connector I figure that any 1/2in plate should be able to take a few tons to punch the metal... maybe 1/32 or 3/64ths thick.

I have read that dies are (re)-'sharpened'.. dies that mean a clean 90deg angle on the punch?

The legs that wrap around the wire are pretty long and thin... can I expect this to be the most trouble? Would doing two operations help or hurt the chances of getting the 'legs' right?

Thanks for any advice.

[J Tiers]

Consider reversing that..... the die of the A2 and the PUNCH of the case hardened. In general that is better.

For this, I'm not so sure, how many do you expect to make? BOTH would be best hardened for significant numbers.

But you may consider a different way, unless you are dead set on an absolute reproduction of the original, because the die is fairly complex in terms of the work required.

Punching the hole AND the exterior will involve you almost certainly in pressure plates, and strippers etc, not a simple punchout die. otherwise the hole punching will roll the material over if done "second", and the outline will do it if THAT is "second". Timed together, exactly, it might work, but I think would need pressure.

And then you need to get it out again, so a stripper of some sort is needed.....

Are you sure some modification to an available part is unacceptable?

[Farbmeister]

I was going to ask about the pressure plate to hole everything.. but didn't want to make a long and detailed post if the initial idea was not sound.

yes, exact duplication is mandatory.. otherwise I would buy 'close enough' off the shelf. Plus 'correct' parts sell for more

So do both die parts in A2, but most likely I will have roll over issues without a mechanical hold on the sheet stock... I have an idea for that.

I did get a commercial quote and it looks like most places will charge $1.50 per at the qty I want. Speed and difficulty is not the issue, 100% reproduction is.

Thank you for the insight.

[Tinkerer]

Sounds like your re making these.

http://www.mcmaster.com/#electrical-wire-terminals/=5wgl40

[dalee100]

Hi,

I generally use S series steels for punch and die sets. I like S7 for punches and S5 for dies. I have them HT'ed to Rc 54-57. I tend to prefer them a bit on the softer side to ensure that the bend and deform rather than grenading if something goes wrong. Though they will wear out faster.

dalee

[Weston Bye]

An alternate plan, though not "production intent", would be to punch out the holes in the blank sheets of material, stack them with the holes in register, then have the stack wire EDM'd to the final shape. The EDM'd surface would be perhaps indistinguishable from the stamped surface, particularly after plating.

[Machinist-Guide]

Shim punch

Farbmeister here is a pic of a shim punch I made from S7. It is used to make shims for prog die sections
You could use this design to punch the blank. It would be cheep and fast to make. You use a hammer to drive the punch.
If you could post a sketch of the blank I can help you more. If I understood your post you only want to stamp a few of these. If so case hard CRS would hold up. If you are going for the long run you would need tool steel The bottom plate works as the die steel. The top plate works as a stripper to keep the stock from bending as its punched. You can bolt and dowel the bottom & Top plate together then machine a hold the shape you want then make your punch to fit the hole. The size of the hole controls the size of the blank. The clearance is on the punch. You should have 10% of stock thickness on each side of your punch.

[IMG][/IMG]

[Weston Bye]

Machinist-Guide,
Yes indeed. I can imagine a punch such as yours, all the same size holes and punches spaced so that multiple parts could be EDM'd from a single blank, or stack of blanks.

[Machinist-Guide]

Pre made punch & button

Another thought is you can buy factory die punches & buttons. You buy the shape punch and button you need then all you need to do is mount the punch and button on a die set.
I will see if I can find a link to the people that make punches and buttons for us.

[Machinist-Guide]

Machinist-Guide,
Yes indeed. I can imagine a punch such as yours, all the same size holes and punches spaced so that multiple parts could be EDM'd from a single blank, or stack of blanks.

I was thinking more along the line of one punch to punch the hole then move the stock over to the next station to punch the blank. The blank punch would have a pilot on the tip to align the hole to the center of the blank.
This would save the cost of wire burning them out.

[Machinist-Guide]

Here is the link

Here is a link to the guys we get our die components from. Take a look at there Ball lock punches & buttons. They will wire burn a button to your specks and grind a punch for it. They also have Urethane Strippers these are hard rubber tubes that slip onto the punch and act as a stripper. Using these eliminates the cost and time of making a stripper.

http://www.moellermfgtn.com/index.htm

[Weston Bye]

I was thinking more along the line of one punch to punch the hole then move the stock over to the next station to punch the blank. The blank punch would have a pilot on the tip to align the hole to the center of the blank.
This would save the cost of wire burning them out.

I like that, too. But better get the shape right the first time or...

All my noise about EDM notwithstanding, I'd probably try first to make a die myself.

[Farbmeister]

That punch picture is a great help to visual what I think I need to do.

The link to the catalog is nothing like what I need.

http://www.parts123.com/parts123/yb.dll?parta~dyndetail~Z5Z5Z50000021a~Z5Z5Z514600~P0.50~~~~S2VD11HGE316824425450b~Z5Z5Z5~Z5Z5Z50000021x

But slightly different. Those are $0.50 each, but I need to go to 8ga... catalog shows 10-16

I got a line on some A2 for cheap, so it will not be much to do a trial run.. heck I might even learn something.

I only need about 20 for my truck.

Typical harness wires look like this:


Then inside a cloth loom.

[Tinkerer]

Well the photo helps... could make those with a Whitney Jr. punch and a bit of filing or a dremel tool and a cutoff wheel.

Go back to the link I posted and look at page 743 Flag Ring Terminals.

[JCD]

I'm not exactly sure what your part will look like, but you might consider o1 for both punch and die. Unless you are planning on long runs of thousands of parts, o1 will work fine, and it is a lot easier to work and heat treat.
Remember it takes about as much force to strip the part from The punch as it does to pierce.