Hello all,
Question for Peter and anyone else who feels they can point me in the right direction
Getting ready to make several aluminum hoods for Nissan S30's (240Z, FairladyZ's). Thought I'd lay out my plan and have you tell me what you think. Not looking to make scrap as Aluminum sheet is fairly expensive.
Material will be 3003 .063. Plan is to make the outer skin in one piece and the inner structure in several pieces. This post is more about the outer than the inner as I plan on making a hammerform for it. We'll see.
Start with a paper pattern off a good steel hood. Make profiles off that hood and mark/label them on it as reference for the new part.
The outer skin is not really a compound curve. It has a lot of shape front to back but side to side is flat with the exception of the blister. There is also a peak in the center of the hood that runs from front to back. It is flat from the side edge to that peak. Being that it is this way my thinking is to simply bend it to the curve (or close to it) it needs (front to back) and then in order to hold that shape do the initial turn of the side flanges over as they will be when finished. (flanges will require a couple of bends in order to finish)
Then block out the blister and the body line in the center. Gather the material with the hammer and dolly and make the center line. Or would it be faster to simply use a chaser after I've formed the blister and make the line?
As for blocking the blister I feel that's pretty straightforward. Block it, move the material around, use my profiles to check progress.
Here is where I'm a little unsure. After I get the blister shaped, if I need more curve (front to back) can I shrink the flanges to accomplish this? Shrink from the very top, same place on both sides? (if shape is needed in the same spot on both sides) Or should I make the curve/bend in the panel, block and make the blister, then turn the flanges? Doing it that way won't the shape/curve be pretty much set after doing the blister and be much harder to manipulate than if I turned the flanges over before blocking the blister?

Question for Peter and anyone else who feels they can point me in the right direction
Getting ready to make several aluminum hoods for Nissan S30's (240Z, FairladyZ's). Thought I'd lay out my plan and have you tell me what you think. Not looking to make scrap as Aluminum sheet is fairly expensive.

Material will be 3003 .063. Plan is to make the outer skin in one piece and the inner structure in several pieces. This post is more about the outer than the inner as I plan on making a hammerform for it. We'll see.

Start with a paper pattern off a good steel hood. Make profiles off that hood and mark/label them on it as reference for the new part.
The outer skin is not really a compound curve. It has a lot of shape front to back but side to side is flat with the exception of the blister. There is also a peak in the center of the hood that runs from front to back. It is flat from the side edge to that peak. Being that it is this way my thinking is to simply bend it to the curve (or close to it) it needs (front to back) and then in order to hold that shape do the initial turn of the side flanges over as they will be when finished. (flanges will require a couple of bends in order to finish)
Then block out the blister and the body line in the center. Gather the material with the hammer and dolly and make the center line. Or would it be faster to simply use a chaser after I've formed the blister and make the line?
As for blocking the blister I feel that's pretty straightforward. Block it, move the material around, use my profiles to check progress.
Here is where I'm a little unsure. After I get the blister shaped, if I need more curve (front to back) can I shrink the flanges to accomplish this? Shrink from the very top, same place on both sides? (if shape is needed in the same spot on both sides) Or should I make the curve/bend in the panel, block and make the blister, then turn the flanges? Doing it that way won't the shape/curve be pretty much set after doing the blister and be much harder to manipulate than if I turned the flanges over before blocking the blister?
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