Lightening holes

[Damn True]

So if one were to put lightening holes into an existing panel or a portion of a structure, how would you apply the bevel to the edge to return the stiffness?

Ive fabbed a component with the holes, and used the next size hole stamp to bevel the edge, but how would you do it on an existing component that is installed into an assembly?

Example:
https://static1.pt-content.com/images/noimg.gif

Now it dosen't appear that he beveled the edge of the holes. I'm wondering if it would be possible to do so.

[Matt@RFR]

That's a toughy. The only thing I can think of, besides an insane amount of mind-numbing body work, is to take one of these bad boys (http://www.irvansmith.com/catalog2/parts/irvan_flare.shtml), thread the hole instead of using a nut on the backside, cut it in halves, insert both halves in the hole and try to reassemble them with a hose clamp. You could probably do it as long as there were some neighboring holes.

Or put a groove in the OD of the bottom die and hold it together with a thick O-Ring that's undersized. I have no idea if either would actually work though.

Looking at that decklid, it almost looks easier to just cut the inner structure off, punch and flare, then weld back on.

[Ralph LoGrasso]

Maybe I'm just ignorant, but I can't see that saving more than 3 or 4lbs on a first gen trunk deck? With the first gen drunk decks weighing in around 35lbs, it just seems like a negligible weight savings to me?

[Damn True]

Not necesarily talking about doing this on a decklid. That's just the easiest photo example I found.

I could save a lot more weight by using a fiberglass decklid.

[Matt@RFR]

Ralph Ralph Ralph. A pound here and an ounce there can add up to a LOT of weight loss.

[Damn True]

Yup, you can try to take a couple pounds off of a few parts, or you can take a few ounces from many. The latter is more work, but more effective.

[Ralph LoGrasso]

I could save a lot more weight by using a fiberglass decklid.

That was the point I was trying to passively make. The only problem with the fiberglass deck lids is they lack some strength. I know you're mostly into the street fighter and more hardcore cars, so I'll assume you'll probably be going with an adjustable aluminum rear spoiler (as am I). I'm not sure the 'glass deck would hold up so well with the spoiler adding all the additional downforce.


Ralph Ralph Ralph. A pound here and an ounce there can add up to a LOT of weight loss.


Haha, you know where my feelings on weight loss fall; I'm shooting for 3000 lbs or less. Disregard my comments :).

[Matt@RFR]

Ralph, that can be taken care of with carefull doubler plate design on the underside of the decklid.

[Ralph LoGrasso]

Hmmmm, now only if there were a 'glass decklid that fit halfway (or halfway to halfway) decent.

[Damn True]

Shhhh

[atomicjoe23]

That's a toughy. The only thing I can think of, besides an insane amount of mind-numbing body work, is to take one of these bad boys (http://www.irvansmith.com/catalog2/parts/irvan_flare.shtml), thread the hole instead of using a nut on the backside, cut it in halves, insert both halves in the hole and try to reassemble them with a hose clamp. You could probably do it as long as there were some neighboring holes.

Or put a groove in the OD of the bottom die and hold it together with a thick O-Ring that's undersized. I have no idea if either would actually work though.

Looking at that decklid, it almost looks easier to just cut the inner structure off, punch and flare, then weld back on.

I second the cutting of the inner structure off, flaring and welding back on. . .with that particular deck lid though (I know you said it was just an example) I don't think that there's enough material between the holes to be able to flare the holes and not destroy the sliver of metal that was left behind. . .the flaring of holes is really common in off-road racing. . .especially the short course and long course off-road racing of the Trophy style trucks. . .those things are AWESOME!!!

[LS6 Tommy]

Ralph Ralph Ralph. A pound here and an ounce there can add up to a LOT of weight loss.

Amen, Brother! Ever see any of the 60's-70's Penske cars up close?
:jawdrop:
Tommy

[atomicjoe23]

I've got to see the vintage TransAm cars up close and in action the last two years running at the Coronade Speed Fest. . .what an event and those cars are AWSOME!!!!

[David Pozzi]

"Flanging" or "Belling" dies are cool. You do need good access to the backside of the piece you are working on though.
On the deck lid pictured, flanging would only add a little stiffness and it's way too hard to get to the back side.