When did belled holes spread from aircraft to race car construction?

And kook at these other holes from one of Cyril's cars

 

I have always heard then called Dimpled, sometimes flared.
The tools are many times called Dimple Dies

 

A couple of shots of the #7 Kurtis Indy car from 1948 driven by Tommy Hinner****z. The rear hairpin gusseting looks like it could have flared holes. You might be able to search out some better pics.

 

The Brits seemed to more enamored with flaring holes than most others. Here's a odball: In 1946 the Lagonda car company (a Bit company that was bought out by Aston Martin) thought they should give Indy a whirl with this **** ugly rig. Obviously it didn't work too well but looks like they kept somebody pretty busy with a flaring tool building it.

 

Balled holes, I like your sense of humor.

Were they bald holes before you modified them? Sorry about that.
,

 

Looks like it to me too. I feel better now, I'll be able to sleep tonight.


It just didn't make sense to me that this method wasn't being used at all.

 

a little OT, but i'm just pointing out that the flaring part of a flared hole is not necessarily a seperate operation.

I punch and flare my 1-1/2" dia holes in 14ga steel in one stroke of the press, no need for seperate dies to do the flaring..



Mine are homemade dies made from mild steel (not hardened), only require a 3/8" hole to pilot the dies. Ive even used the same dies to punch a flared hole in the middle of a panel by placing them on the floor and using a sledge for power instead of a press. I've punched thousands of holes using the same set of dies. Sharpen the male die with a lathe cut maybe once every 6mo or so, never had to do anything to the female die.

 

The proper aviation term is lightening hole ....

 

http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19930093371_1993093371.pdf

Some cool info on them...

 

Absolutely amazing the stuff that turns up on the HAMB! I have to print this out and sit down and digest it. Fantastic post!

 

I always heard it called "Marsden Mat"
http://en.wikipedia.org/wiki/Marsden_Matting
I'd love to have a bunch of that in front of my hanger.

 

.....oh all the racecar trailers I could build from that.....heaven

 

You could hear a car trailer coming from a mile away when that mat was used. The So Cal dune buggy crowd used the hell out of that stuff in the early sixties.

 

They were used on the 1910 Junkers J-1 Monoplane.

Doc.

 

Wow. Thats gotta be the first. Really glad I asked, turned out to be an interesting thread.

 

When Hudson Motor Car Co. introduced the Terraplane models in mid-year 1932, they had a stout new belled lightening hole X-member in the frame.

I recently corresponded with a fellow who I believe wrote that the first use of belled lightening holes in the US auto industry was the 1928 Stutz cars.

Isn't the general rule that anything done in production cars is usually pioneered by racers?

 

The aircraft flare is different from the racecar flare. I have some of both and the aircraft flare is much deeper and pronounced. I believe it is a safety thing so they don't have sharp edges. Racecar flare are more a tip of the edge and they are sharper, if you reach thru one of them you'll know what i mean.

 

Porsche 550 factory race team lightweight hill climbers were using belled holes extensively by 1954/55

 

The Junkers J-1 wasn't built until 1916, but that is still pretty early.

 

The metal sheets (PSP, as several others have pointed out) were made to interlock for use as quickly-built airplane landing strips, mostly in the Pacific theater during the island hopping campaign... it is still used today on US bases in Afghanistan & Iraq, as well as in many other places around the world.

My neighbor has some of the extra heavy u-shaped posts designed to work with it, as fence posts. Lots of surplus stuff has also found use as corrals out here in cattle country, to be used for working cattle (that's what they call it when the cowboys castrate, brand and give shots to the bull calves - turning them into steers...)

 

...

 

I was wondering about the history of lightening holes in production vehicles. Nash must have started using them in the late '40s or very early '50s, as my '52 Rambler has them in two areas on the inner body structure. They appear to be a close match to the standard flared hole profile, but it makes sense they'd be used on a unibody vehicle where both strength and weight reduction were desirable.





Rear cross brace, just under the rear seat's leading edge:

 

Miles of psp used in Vietnam

 

The S6b, built for the 1931 Schneider, was able to get to 2400 hp.

 

An old thread resurfaces...

Looks like the Pre-War Mercedes Silver Arrows used lightening holes (some belled) on the ch***is of their F1 cars. 1937 W125 ch***is shown below.

 

On this side of the pond, they're usually called 'swaged holes'. Swaging (pronounced sway-jing) dies can be made quite quickly on a lathe; I made this pair of dies for this job. I've never needed to use a press to swage/bell/dimple a hole, although it would probably be a good idea to make a press tool that punches and swages the holes if you have a large number to do.

 

My Morris Minor had eight such holes in the engine bay, four in each of the tie plates connecting the ch***is legs to the inner wings. The design first appeared in 1948.

 

You realize a lot of California hot rodders had day gigs working in aircraft plants , don't you? It's called technology transfer.

 

Somethings, like this, I say are impossible to put a date too.

Some kid in dayton Ohio was probably working at an aviation plant and did a couple panels during lunch to see how they'd look as a separator panel between the trunk and back seat in his jalopy but his buddies thought it looked stupid and that was the end of that even though the kid left the panel in there for years.

It seems that when certain things are "written in stone" somebody else comes along with proof that-that piece of stone was actually marshmallow. Don't know how many times I've seen that happen here on the board.

So the question becomes not when it was first done but when did it become mainstream? Personally I like stuff before it becomes mainstream, before it becomes a cookie cutter operation where every car has the same basic details.

I love early customs because of this, guys playing around with styles and designs, dual headlights, then it became a fad, sunken antennas then it became a fad.

And I think that's exactly what Ed Roth was trying to get away from and why he became so popular.

 

Boeing was using hydroforming to cut and flare holes extensively in the early 50's. About that time I noticed it on streamliners and belly tanks at Bonneville.