TOPIC:

I began this post to separate this part of my build from my project thread to cut down on thread load times and aid in future searches. For the benefit of anyone reading this that has not read my project post, I will start from the beginning

Here are the base materials for my frame jig
I have (2) pieces of 2"x3"x6.5' rectangualr tubing. (4) peices of 1.5"x1.5"x18" square tubing. (3) peices of 2"x4"x12" rectangular tubing and (1) 2"x4"x18". All tubing is .120 wall mild steel tubing. I will need some more material for fixtures, but I'll get that later.

Now that I have something to modify my frame for (SSSA ) I thought I'd get started on the jig while my engine parts are out being matched to my cases

The 1.5x1.5" tubing is the transverse support for the main 2"x3" longitudinal jig base. Of the 4 transverse braces, the outside two will be located 5" from the end of the main rails. This will place them close to the wheel axle supports without being in the way. The other two will be located under the swingarm pivot and the engine cradle. Now, I need the fixtures (made of the 2"x4" tubing) to be tight between the main longitudinals for accuracy, but slide in easy without a beating by Uncle Ned (my sledge hammer)so I made a .030" shim by using 6 sheets of printer paper. I also clamped one of the other 1.5"x1.5" tubes to the top side of the longitudinals. This will act as a strong back and help prevent the main rails from rolling off of level when I start welding.

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Another angle..

And a closer look...

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It's so pretty! All this work just to install this silly little piece of aluminium (as the Brits say) and steel!

OH GREAT. Now u separate it. I just posted pics for this in your other porject post. thanks a lot.
lol just kiddin man.

If u have a provision in your jig for a steering head and swingarm pivot point , u could easily do some frame flex tests.
u just mount the sw arm pivot in the jig. fasten jig to floor. place a steel bar in the steering head and flex the neck downwards toward the sw arm pivot. Then twist it. if u can somehow attach a scale, u can apply a measurable amount of force. u can test to see how much force it takes to flex the neck x distance. then u can brace the neck and repeat the test at the pivot area.
once u do that, u can add a gusset and retest.
This can even be done on a small scale model.
I believe this is how Tony Foal does it.

cant wait to see the finished project

Hey Mark, I have thought about testing the frame flex after reading Foals work, and I'm still thinking about it. I'd like to do it, and I'm sure I could quantify the results (deflection amount vs force), its just a matter of working out the details and the extra time involved. Although, if I did tackle it, it would provide some valuable info on what bracing works and how well it works I think that if I had another KZR member close by that was interested in helping me, that would go along way toward convincing me to do it. Any takers?

So I welded together the frame jig this evening. Since all the welding supply dealers are either closed on Sat. or closed early, I couldn't get any argon. So, I stopped by Harbor Freight and picked up a spool of flux core wire. Not my first choice (or 10th for that matter) to use on the frame, but it'll work for the jig construction just fine. Here is the jig with the transverse braces being welded in place

got the sequence mixed up here

what are you using to weld that,flux cored mig?