What size (tonnage)press whether arbor or hydraulic would I need to punch out shapes in copper and aluminum approx. size 139.7mm X 66mm X 0.5mm ?

It's a straight forward calculation based on the shear strength of the material and the perimeter of the cut. Don't forget to factor in the thickness.

Does that help? I am no expert, but I see nobody has replied and I have jumped through these hoops before so I thought I would chime in....

Scott

Well thats better than nothing response. I,d be glad to do the calculations if I could find the shear strength of copper and aluminum at .5mm thickness.

So, according to my Machinist Handbook the 'rule of thumb' is:

Round Holes:
steel diameter x thickness x80 = Number of Tons
brass diameter x thickness x 65 = Number of Tons

Any other Holes:
steel Perimeter x 1/3 x 80 = Number of Tons
brass Perimeter x 1/3 x65 = Number of Tons

Aluminum Mechanical Properties
ALLOY AL 6061T-6
Tensile Strength (ksi) 45
Yield Strength (ksi) 40
Elongation (% in 2") 17
Shear Strength (ksi) 28
Hardness (Brinell) 30


Scott

Thanks guys looks like I,ve figured around 5 1/2 tons to press out what I want and I figured purchasing a 10 or 20 ton press should work.

ZipSnipe...keep us updated on your progress...maybe even some pics...

Unfortunetly it won,t be until March or even April till I purchase any new equiptment however in the mean time I,m doing mega research on cnc, and everything I need to do metal fabrication (copper and aluminum) once again appreciate the help. And of course I,ll supply pics.

Well, it appears I need at least a 35 ton press to do the work I need myself.. but a punch press of substantial quality is going to be procured. I'm still working with a press manufacturer to design a single station press that has a bolster plate that I want so that it holds a single 28xx setup.. and will allow me to fixture parts to the plate up to indexes / stops. This will be a 2nd operation press.

I used to run a monster press.. a Heim Rouselle G1-55 55 ton OBI press at the shop I used to work at. Most of the 6" x 12" dies were about 35 ton max. It's a wonder how the press never broke the dies.. being 20 tons over max.

I had our AMADA CNC turret press operator/set up guy punch out parts that I was rejecting a lot do to ill-constructed dies. No matter how much we sharpened and lubed the dies, they wouldn't cut 100% perfect parts. Parts such as 1" x 1" thin aluminum squares with a small oblong slot in them were the worst cause they would get stuck in the die cork all the time. Parts like that would take me hours to press out, in what he could do in minutes.. and literally hundreds of them.

Basically before you go on to your manufacturing make sure you got a good die design, that your tonnage is right, you are properly lubing your stamping dies and mat'l, make sure you are using a good stripper and your clearances are right. You can always call Danly or Lempco.. and they'll help you.

Greg

Thanks for the response Greg, but I have since changed direction on the product i was going to produce. But it was nice to learn what it would take to make the part.

I knew this thread was a little old but well, even if you had done something else with your project, I wanted to post my $2 worth because you will never know whom may read the thread and need the information.

Greg

Good point the more info people can pick up the better.

yep, certainly.. whilest we are here on this earth and here in this forurm we might as well learn something.

Greg

appologise if I'm interupting or on the wrong chat room sight new to the sight and just getting use to it! Desperate to know what sort of machine you guys think I should get for making 2d coin dies, I will be doing very fine work and looking for a 1:1 pantograph/mill, any comments would be much appriciated.

For 2-D and modelled (2 1/2-D) dies you need a pantograph adjusted to about 4 to 1 ratio, master to die. The Gorton P 1-2 is an ideal machine; the Deckel is also excellent. I have three Gorton machines and can say you can"t go wrong with a P 1-2.

Thank you Die cutter, I have a great looking original that I want to copy exactly
the same size etc. Will the machine you suggest do it without me having to enlarge the original first? Also how fine does it go down to and whats a good price to pay!

Tomst,

There are accessories for some pantograph engravers to allow 1 to 1 reproduction, but the result is never as good as the original. For duplicating an existing coin, most mints use a ram edm when the cost of a full resculpt is too expensive and/or time consuming. If the coin is 2-D it should be fairly easy for a graphic artist to reproduce the image which is then made into a master plate 4 times the size of the coin. This master is then engraved on a pantograph in the usual way. If you would post a photo of the art it might help as far as ideas.

Will try to post but i've only just got my head around e-mailing and this chat room but will give it a go over the weekend. Thought with computers nowdays it would be easy to make a like for like, mind you it may take me a year to work out how too!!!

die makers handbook, 14 bucks. has the calc.