My Shop Wins No Awards For Organization

To hold the bottom frame tubes exactly where they should be I cut 2 pieces of 1x3" steel wide enough to clear the frame tubes and then some. I scribed a center line then measured where the center of the tubes should be on either side of the center line. these 1x3 tubes measured almost exactly 3 inches and the frame tubes were modeled parallel to the ground and exactly 3" to the bottom of the tubes. So I milled a couple of tabs with a 1-3/8" end mill to make saddles to locate the tubes on top of the 1x3's. In the Bridgeport it was easy to get the depth accurate and scribe a line to line up with the locating lines I had scribed on the 1x3's. once the saddles were tack welded to the 1x3's I measured the distance from the front swing arm pivot and with the large square located the 1x3's on the frame jig. All in all it is very well lined up.

Jiggin

 JD2 model 32 bender (hint It Rocks!)
P.S. Scott you laughed at my stand.
It will kick your hossfields ass!

I hate building fixtures. It really is a necessary evil. Without a jig the chances of a weldment coming out straight or proper is almost nil. especially with a frame like this the jig is a way to lay everything out with flat and square references. in fact it would e very hard to measure the angles and relative positions of the tubes without the jig. I designed the jig in solidworks to the frame model. With reference geometry that is spaced at whole inch increments it is very easy to create and locate fixture parts even with a tape measure and have a finished frame that is functionally very close to the model. I hate making Jigs. I know there aren't any pictures of the fixture here (I will get to them now that I have an idea if how I'm going to do it) but I spent most of the day trying different ideas out in CAD and now will start making the parts..

Main Frame Tubes Together

Assembling the frame Part 1