The struts needed to be notched to give clearance for the other struts near the bolt hole. I looked into welding thicker tabs to the end of the struts. The metal needed ran about $300, which would have been six times the final cost.
I looked into making hub plates, each different type of intersection would have a specially designed plate with the needed angles built into the plate. Not only did this involve more metal but there would be intersections that needed up to 24 bolts. Burning Man is only a week so that was out of the question.
The simplest method was to cut one edge back on the angle iron. It would have to be cut back considerably for intersections of 12 struts. To simplify assembly I decided to cut all the struts back the same distance. This way there would be no question as to the direction of the strut, workers would not need to worry about what type of intersection each end was going to.
The notching process began with a custom made jig fitted to the chop saw to do the long cuts. Over 500 of these cuts were needed.
The short cut was made with a 4 1/2" grinder.
The angle iron had an internal fillet that needed to be ground down. The grinding would involve three 4 1/2" grinders and a 9" angle grinder. Work areas were set up in both the front and back yard. Two weeks in a row were used to get all the struts cut and ground down ready to be drilled.
