ok, i need to make a couple of brackets, and i want them totally uniform, obviously till now, strangely i have only had to make one off's of any brackets for the willys. i want to make an "eye appealing shape", and thus curves and rounded corners. as these are going to capture rod ends, they are going to be right next to one another and need to be almost perfect. if they were only straight pieces of steel, i'd just slice em off with the skill saw and the metal devil blade and call it done... but my question is, if i make a template out of steel, get it exactly the way i want it, then use it as a pattern for flame cutting the rest, how far/close should i get to the actual piece cutline with the torch? my biggest concern is fucking up the strength of the metal with the heat? am i worried for nothing? thanks
Cut it fucker. Thousands of racecars and hotrods were built with torch before the days of waterjets and plasmas.
Cut em both close, lay em together and tack the edges in a couple/3 places. Thes use your spindle/drum sander to make em the same shape.........
Tman beat me to the punch about stacking them together to final finish the shape. If the metal is just common carbon steel, flame cutting shouldn't be a problem. If its a high chrome moly steel, I'd consider a plasma cutter. Too much heat is not the best for the higher alloy steels. On this note, I read an old article on Bill Niekamp's AMBR winner. He is supposed to have cut the bracket pieces with a hacksaw by hand because he didn't want "lock in a lot of stresses" cutting them out with a torch.
I have made cutting patterns. It is just like a pattern cutting machine would use but I did not have the machine. I made the patterns a little under size and clamped or bolted them to the steel. I spaced them up a bit and just dragged the torch around them. You have to experiment to figure out how much under size to make the pattern. Varies with cutting tip. I used about a 1/16 to 3/32. I made the patterns from 16 ga. Worked really well.
Heres a tech on making identical brackets. http://www.jalopyjournal.com/forum/showthread.php?t=144787
If the brackets have bolt holes in them, lay out and drill your bolt holes before you cut out the shape of the bracket. Then make holes to match in your pattern and bolt the pattern to the steel plate. Then after you cut them out and knock off the slaggy junk, bolt them together and grind them both to shape. If you need to make 4 brackets, you can bolt all 4 together with long bolts and grind them as one and they'll all come out nice and identical. That's how I made my 4-bar brackets for my rear suspsension. I made the patterns out of masonite and used a plasma torch though. It's a lot easier to drill the holes BEFORE you cut out the parts with a torch though.
seems to me they used to have a device that bolted onto the cutting tip the looked like a pointer that would follow a pattern. a flange cutter? saw it at a goodguys show i think in pleasanton and it had wheels for long straight cuts that were removable and a pointer that bolted in their place to trace patterns. small,compact and light.
When I make brackets or parts, I make a template and layout the part on the steel that I am going to cut. After laying out the part with a scribe, I take a center punch and make center punch marks right on the scribed line all the way around the part. When I cut the part out, I stay just outside the center punch marks. The marks allow you to retain the outline of your part. It's time consuming to center punch around the outline but it insures that you have a guide for your finish size. After I cut out the item, I usually grind it to final shape and grind just until the center punch marks disappear. As others have stated, you can stack pieces together and tack them to make identical parts. A boilermaker gave me the tip on using the center punch method of preserving the outline of flame cut parts. Try it, it works.
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