Stamping/pressing/punching holes in 5052

[Sonicmook56]

Hey gang-

First off, I have no experience with this type of work.

I'm looking to speed up a manufacturing operation and I think stamping/punching/pressing might be the way to go.

Aluminum is 5052, .063" thick. Only the large holes on top would be punched, the other countersunk holes will be done with a CNC mill. Plate is cut to size by my supplier.



Is this something that would be easy to do in house? I own a 12 ton floor press, would this coupled with a proper die work?

Could I DIY a simple die like this on my bench top mill with little headache or is this best left to professionals?

Anyone recommend a company to produce these die's and how much would I be expected to pay?

~B

[Sonicmook56]

I was thinking something like this:



possible, or better to mill out each piece? I can't imagine ever going over 1,500 pieces. Doing runs of about 40 pieces at a time, as I need them.

[One of Many]

Originally Posted by Sonicmook56 I was thinking something like this: possible, or better to mill out each piece? I can't imagine ever going over 1,500 pieces. Doing runs of about 40 pieces at a time, as I need them.

You have a close idea;

For every inch of periphery on .06 aluminum it can take up to 3/4 of a ton. Calculate your total periphery for a crude tonnage to punch it. The punches could also be staggered to lower that tonnage rather than punching all at once.

I wouldn't cut the indexing recess into the plate. Use pins so all that material doesn't need removed. Add a stripper plate above the surface and make the punches go through the stripper plate and strips it free when the upper ram goes back up. The lower die will need bolted down of course.

The dies should also be hardened to at least a 58Rc. Then ground for a nice sharp edge periphery.

Also consider the alignment between the upper and lower dies. The clearance between the upper and lower die is 7-10% of material thickness. With less than .006 around the die, it better be aligned to minimize tonnage to punch and never clash cutting edges. Normally this is accomplished on a die shoe with alignment pins that keep the dies stationary to each other. You could press the pins into the lower plate and slip fit them into the upper plate. One concern is that the upper die never leave the pins and the press should have enough rigidity to maintain that alignment. Not likely with a bottle jack press....and off center loading. The punching load is not equally balanced either. The likelyhood of the dies surviving depends on a decent setup.

Not to rain on your parade, but this is where one must look at the economics and part quantity to get the expense or effort in tooling costs to pay off. Labor over time or labor up front meet somewhere in production demands. If you can equate the two relative to the burden of overhead and production counts, you know which direction you should go...Normally in the 10's of thousands total product life. At 1500 anually it could take 10 years to recover the cost to have the die made. That is only a guestimate of the difference in creating chips and maintaing the dies.

Not a slam dunk, but I hope I have offered you a comparative picture of what you face when going with a punching die.

DC

[PhoenixMetal]

This kind of part is the domain of a turret punch machine. Even the countersinks can be done (a special countersink tool and its corresponding prepunch round tool for a turret costs around $450).

It looks like you are generally focused on building these yourself (I'm the same way), but it really is such a simple and quick job for a shop with a turret - so you really might want to look at sending this job out.

1500 pieces isn't a large enough quantity to justify the expense and headache of building a dedicated die to punch it out in one shot. My guess is that a shop with a turret will be able to bring it in at below your cost (either if you were to continue to mill them out, or if you tried to build that die).