Dimple on aluminum

Is there a tool which will let me create a round "dimple" in 5052 aluminum?

Like maybe a punch and die that won't punch through but create a "half round" in the metal?

I have a nice roper whitney bench punch (17 -- it's a big one) -- I'll try that first, I just won't punch all the way through -- but I need something more accurate and consistent.

I want to be able to slide a faceplate on an aluminum chassis and have it catch, yet still be able to pull it off. Have seen catch rollers -- don't want those.

Reply to
mkr5000
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mkr5000 fired this volley in news: snipped-for-privacy@googlegroups.com:

I'd think if you just "bull-nosed" (hemispherical) a HSS blank to fit the punch, then stopped the handle at the point where the equator of that nose came flush, it would work just fine.

Lloyd

Reply to
Lloyd E. Sponenburgh

Agreed. May take a little bit of adjustment to get the depth / deformation the way you'd like it.

Reply to
Joe AutoDrill

"Lloyd E. Sponenburgh" fired this volley in news:XnsA14885E413D18lloydspmindspringcom@216.168.3.70:

One thing, though. The radius of the bottom of that dimple will be greater by the thickness of the material than the top. If you want the top sheet dimples to "key" into the bottom sheet dimples, you'll need a smaller punch tip radius to do the top sheet than to do the bottom

LLoyd

Reply to
Lloyd E. Sponenburgh

in the metal?

first, I just won't punch all the way through -- but I need something more accurate and consistent.

catch, yet still be able to pull it off. Have seen catch rollers -- don't want those.

What's the thickness of the aluminum and the size of the dimple (diameter and depth)?

5052 has pretty good elongation and ductility. You're talking about stretching (drawing) the dimple. That will work well if the dimple isn't too large. If it is large, the hammered-punch-and-die approach will wrinkle the metal around the dimple. It's a matter of the diameter relative to the thickness.

Assuming the dimensions in my mental picture, it should work well. You don't need HSS or tool steel, unless you're going to punch hundreds of them. Any mild or alloy steel you have on hand should work.

If you only have to do a few and if there is a ball bearing of the right size available, you can use that for the punch. If you really want to get quick and dirty, and if the depth of the dimple is shallow, get a few ball bearings and use the first one or two to pound the die shape into a block of aluminum or copper. It should hold up for drawing a few dimples, at least.

Scraper

Reply to
Tim M

ound" in the metal?

ry that first, I just won't punch all the way through -- but I need somethi ng more accurate and consistent.

t catch, yet still be able to pull it off. Have seen catch rollers -- don't want those.

Even hardwood would work for a backup piece for 4 feet on an electronic case, for instance. The semi-pro electronics suppliers used to have an arbor press with attachments to make louvers, punch holes, and make foot bulges for cases. Wanted a whole lot of cash for stuff that a guy with a few tools could make for himself. The thing with the arbor press was that you could set a stop so the ram stopped at the same point every time, needed if you want a case that doesn't rock.

Stan

Reply to
Stanley Schaefer

round" in the metal?

that first, I just won't punch all the way through -- but I need something more accurate and consistent.

catch, yet still be able to pull it off. Have seen catch rollers -- don't want those.

Yeah, that's a good point. You could do a lot of re-whacking to get all four exactly alike.

I agree on the hardwood. I have some hard maple blocks that I use for all kinds of raising and sinking jobs around the shop, mostly for making decorative items out of aluminum or copper. I think it would work here. Soft aluminum works, too.

Scraper

Reply to
Tim M

Maybe brass BB, and use soft lead for the anvil?

Christopher A. Young Learn more about Jesus

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Like maybe a punch and die that won't punch through but create a "half round" in the metal?

I have a nice roper whitney bench punch (17 -- it's a big one) -- I'll try that first, I just won't punch all the way through -- but I need something more accurate and consistent.

I want to be able to slide a faceplate on an aluminum chassis and have it catch, yet still be able to pull it off. Have seen catch rollers -- don't want those.

Reply to
Stormin Mormon

Look for "dapping punch". Of course, this depends on how thick the metal is.

Look here:

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You need the punch and a block -- and for convenience, go for the combination of the two, such as in SGR4-JT3405DS

This will allow you try various sizes of dimples. It is driven by a hammer, FWIW.

Agreed -- which means that you need the right size of hammer and to develop a repeatable stroke to get the same size dimple.

O.K. You could modify the dapping punch to work with a hydraulic driver for repeatability.

Good Luck, DoN.

Reply to
DoN. Nichols

Whack it with a ball peen hammer?

Why does the guy whose friends all tease him about over-engineering everything have to suggest this?

Reply to
Tim Wescott

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