how were belly tanks made?

Here is part 4 from a 1937 Chevrolet film. They are stamping tops and fenders, I bet the tanks were done about the same way. Parts 1 thru 3 show the engine being made.

http://www.archive.org/details/MasterHa1936_4

Joe

 

Thanks for that link Joe. I didn't know that archive existed.
Jeff

 

Rich, how about going the route of Britain's Mosquito?

 

Most were stamped. In some cases the ends were spun...

 

That was cool to watch, thanks for posting

 

That is a wicked**** good movie clip! I am totally amazed at how smooth all that stuff worked together.

 

People would freak if they knew what the wings of commercial aircraft are made of.....that have been flying for 20 years!!!!

 

Damn, that's what we need more of in this country, kick-ass manufacturing - - get people working; if everyone had a good job we would not need to worry about government health plans.

 

tops and bottoms of P-38 tanks are very similar:

 

Are the ripples from the stamping process or baffels?

 

I thought it was funny watchin the guys mark the dents in the roof in that clip.

 

The Mullins manufacturing company that made the Mullins Red Cap trailers also made drop tanks for the USAAF and Navy during WWII.

 

they're from the stamping.

Dave

 

ThunderRocket, P-51's went no where near 400 in level flight, in fact, some models of the "doggy" P-40 had a faster cruise in level flight. P-51's didn't even cruise at 300.

 

The ripples are from the drawing process. These tanks were drawn in one hit. The wrinkles are from uncontrolled material gathering were the material flow is under compression. In the drawing process, the material is both stretched and compressed. In the compression zones, you need pressure to prevent the material from folding over itself. When doing irregular shape draws like a tank, there is no way to exert pressure on the material after it leaves the draw pads so it is free to flow where it wants.

The steel tanks are made of low carbon AKDQ (Aluminum Killed Draw Quality) They add aluminum to the molten steel to make the material stretch better with out tearing.

The aluminum ones were made of 5052 H-32. In most cases the 3XXX series aluminum didn't have the tensile strength needed to draw this shape. And the 6XXX series aluminum would work harden too fast. The 6XXX aluminum also wasn't the best for welding.

With the tooling technology that is available today, and the ridiculous amount of idle automotive presses, At $10,000 - $15,000 a pop for a good tank it wouldn't be a bad project for an enterprising automotive job shop.

MY $0.02
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Thanks Daddyo, Is a draw just a slow stamping? The whole process is fascinating to me, stopping the upper die so it doesn't damage the lower one must be a heck of a process for the setup guy.

 

Super cool Toner! You gotta get some video of that beast.

 

Draw work is a form of metal stamping. It can be done on the same equipment. We do draw work on both mechanical and hydraulic presses. The hydraulic presses are capable of doing deeper and more difficult draws because of the slower and constant ram speeds. Mechanical presses accselerate to the bottom of the stroke and slow down as it reaches BDC. not the best condition for draw work.

The set ups aren't much different then regular stamping dies, but parallelism and perpendicularity is far more critical.


Here is one of our hydraulic presses. It is 300 ton 36" stroke press. The wheel half that he is holding is 3/16" aluminum.

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Sorry for the side track on the draw thing. I hope it explains how the metal tanks were made.

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Per Crazydaddyo:"The steel tanks are made of low carbon AKDQ (Aluminum Killed Draw Quality) They add aluminum to the molten steel to make the material stretch better with out tearing."
Sorry, but Ak steel was not available until the late fifties. (Think deeply drawn auto quarter panels such as 1959 Chevy).
I do know that Ford Motor Co. produced drop tanks for WWII.
So, Lucky, you may be just drivin' an old Ford out there on the salt !

 

O/T - sort of -- check this video of drawing aluminum into cans

http://www.youtube.com/watch?v=SJNw...8CE45CC7C&playnext=1&playnext_from=PL&index=6

 

Not true.

Go here and read the page from the flight manual listed in the first post:

http://www.ww2aircraft.net/forum/aviation/p-51-cruise-speed-395-mph-tas-808.html

With great******* rolling mills, that's how.

When you break a 1,000' long ship up into 10' wide sections, you find that there isn't a lot of shape in one of the directions, so the majority of the hull plates can simply be shaped in a three roll mill.

The more complex shapes are either cast as one piece, or broken down into pieces that can be rolled in a three roll mill.

The force required to shrink or stretch hull thickness material is simply too great. That's why you don't see a lot of high crown panels made from a single sheet of 1/2" material.

 

I fully understand the need for the series of "bumps" down the sides of the P-38 tanks, but I thought I read that their location had to do with breaking up the boundary layer of air so they would be more stable at speed.

 

Alright guys I finally got some video's for you.

The first is my press, a 2500 ton transfer press. Just to give you an idea of scale the windows in the sides are a little less than 4 feet square.

In the video the first die is making a firewall stamping in one shot. The other 4 dies are for punching holes and a restrike die (making the flanges at the edges)

It has a vacuum cup system to unstack the steel & magnetic conveyors to feed it into the press.then the feedbars (yellow things moving back & forth) transfer the stamping from one die to another.

The first (draw die) weighs about 19000 lbs for this die set & the others are between 13000 & 18000 lbs each. Making this part the press makes 15 strokes (parts) a minute. Depending on the part this press has the ability to run at 25 strokes per minute.

Turn your volume down. These*****ers are loud! and maximize it on your screen, not sure how good the you tube video upload is but the copy in my computer at home is very clear. If you guys have any questions I will answer as best I can.

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The second is a 600 ton coil fed blanking press. basically a big set of steel scissors. it can (and usually does) make 50 strokes a minute.

The steel is unwound from the coil & runs through a straightener to take the curve out of it from being coiled up. Then it runs through a loop pit, basically a 30 foot deep hole to relax any twist in the steel. Then through a feeder accurate to .2 mm when feeding. The die cuts the steel to the set length & then drops onto the conveyor belt. The steel sheets (blanks) are stacked at the end of the conveyor automatically & then shuttled in & out automatically when the stack reaches a pre-set quantity.

At the end of the video you can see the different sizes & shapes of stacked blanks in the blank yard. There is about a 35 second pause in the middle of the video, I was recording & it hit a full stack & stopped long enough for the piler trucks to switch. It auto starts again with no command from the operator.

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That. Was. AWESOME.

God I love tools.

Just as an aside, I'd love to have the coinage spent on that machine rolling around in my pockets just now. lol

Boy howdy was that cool.

 

The third is an 800 tom progressive coil fed press.

The first three steps are basically the same as the blanking press. Straightener, loop pit, feeder. The die inside the press has several stages that the steel feeds through to make a completed part come out the end. The steel is trimmed to the part size, the part is formed, holes are punched, it is restruck to final shape, a few more holes are punched & it cuts free at the end & drops onto the conveyor belt. Then an operator stacks he parts into the bins for shipment. (I did not record that part)

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The transfer press is around 25 million for the press & the tooling.

You would need a pretty big garage to store the*****er, as I said before it is somewhere around 40 feet from floor to the top & there is another 15-20 feet below ground level.

There is a scrap conveyor system under all of the presses to catch the excess scrap metal. Somewhere around 1000 feet of conveyors all together just in the scrap system.

There are 7 presses in our shop, in addition to the three I posted there is a 3000 ton press (about the same physical size as the 2500, just heavier duty. think, 1/2 ton vs. 1 ton trucks), a 1500 tom & 2, 250 ton little guys.

And since I know someone will ask, Those presses are making Honda parts. I don't drive 'em, I just make parts for 'em.

 

That was some cool video!!! There was a good thread over on Metal Meet showing some hydroforming of wheel pants for aircraft. http://www.metalmeet.com/forum/showthread.php?t=13341&highlight=HYDROFORMING
It was very encouraging to see, because it looked like it could be done in a home workshop.
Jeff

 

Cool press videos!

Hydro-forming wasn't around in WWII, so they had to have been stamped...

 

thanks to everyone for all the feedback and cool videos