chassis jig design

[raustinss]

Gentleman....watch what you do with beams, as you may think they are straight and true....they aren't. The way they are made in the mills leaves lots of room for variances...you can have two beams which are the exact same spec but have more then 1/16" difference in height. Unless of course they came from the same length of material. Also the top and bottom flanges may not be perfectly parallel to each other. This is why alot of shops end up using tubing, the way tubing is specified eg.4" square....1/4" wall....it won't have a fraction of the variances that beams have..it's what is commonly called nominal or non nominal diamensioning. The roadster shop makes their frames on jigs made from either 3" or 4" tubing. If a customer was to come to my shop to have a chassis jig made I would heavily sway them towards using tubing over beams.
Ryan