chassis jig design

[wellis77]

Glad this was recently brought back up. I'm going to be building a table for myself in a couple months and have recently been thinking about the best way I can weld this together to avoid warping. I've read through this thread many times and have read about bolting top rails to the frame of the table to avoid warping but I'm having a hard time picturing what that looks like. Does anybody have pictures of this type of design to give me an idea?

Otherwise, what are some ways I can avoid warping, as much as possible. Until earlier this week, I figured I would stitch weld 1 - 1 1/2 inches per leg, then about an inch on each side of the 2 x 2 cross braces. From other threads I've read that seems to be a pretty common way of welding a table together. Earlier this week I found some "welder angle clamps" and it got me wondering if this might be a better option. At $40-$50 a piece plus shipping, they aren't cheap but it may be worth it in order to be certain. Any thoughts on these clamps and if they would be worth the investment for a one or two use table?
http://cgi.ebay.com/4-Industrial-Wel...#ht_2871wt_907




Below is an image of my design so far. I'm planning a 15' table with the side rails out of 3x3x1/8 box tube, cross braces and angled leg braces out of 2x2x1/8, legs are 2x3x1/8. I'll be building adjusters into each leg in order to level it out.


I appreciate any feedback on my design and questions. Thanks everybody.