Speedchop Arie: We are not using a frame-jig. We never do! We just draw a heart-line on the floor to keep everything straight. We first tag welded all modifications we did toady and then did all the welding. While welding our centering-rod moves all the time. By changing location with the welder we influence the rod. At the end of all welding the centering-rod should be still on the heardline. And yes it was. We have done a dozen of frames now and all are handling flawlessly. Not one cracked or anything eventhough most make many, many miles.