I welded up a frame JIG to start welding and boxing my Model A frame. I need to replace the front cross member and was curious if anyone has a pic of brackets or mounting points for a frame on a JIG. I want it to be flat when I take the front cross member off & weld on a new one. I have seen a lot "C" clamp the frame to the jig, but was hopeful that someone had some easier or better way. I was thinking I need to weld up some bracket, but thought I would ask for pics to see what others have done.
Don't try and build the fixture so that the solid uprights are directly in contact with the frame rails. Instead you want to be able to shim the frame square. I used long pieces of perf tube to clamp onto the "legs" of the channel. You'll notice the drop lip on the bottom of the channel that further complicates things. The nice thing about this setup is that we constructed the whole frame in the jig and only had to remove and re-level/square up a few clamping points when we got to the boxing stage. I did have weld nuts at the front and back for bumper mounts that I was able to use but these points were a lot harder to shim up. The clamps that touch both top and bottom "legs" makes it really easy to twist the frame into square with shims. Strings run front to back ensured we weren't pulling a bow into the rails along the length and the top of the rails are level so everything was worked to level. Important to have a very sturdy base so the only thing moving as you shim is the frame, not the jig. Frame is to print and square within 0.030" Next time I'll build it so I can stand between the rails to weld. In the thread linked below is a pic of me welding sitting on the table and that's one of the least awkward positions I had to work in. More here: http://www.jalopyjournal.com/forum/showthread.php?t=291794
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