Hit the local scrap yard for used steel, especially pipe. I have built over 50 12 module racks using this design, delivered them hundreds of miles to three different states, no failures in over 20 years, all using locally sourced material, used and new steel, so for sure less expensive then "store bought". I had many customers run the numbers, over me delivering this racked and quickly mounted array, over them buying store bought, paying freight, having to assemble and mount the module piecemeal, the cost difference was huge! I sold the PV 15% above my cost, the real money was in the racks fabrication, while still being the best bang for the buck. This also meant I could do 90% of the work in my home shop, at my own pace and when i felt like it, not repeated travels to a job site. One huge advantage, for me anyway, was I could lift the array with my boom truck with all the modules on it and prewired. No awkward work installing them on the rack off ladders or scaffolding. I used 6 to 8" sch pipe for the cross arm, 2" x 3/16" angle, and 1 1/4" x 1/8". All the lengths worked out almost perfect, meaning almost no scrap left over from standard lengths. I was knocking these out in a easy day, by noon the next day they were ready to truck to my job site and set on the already installed 8" pipe. I could be "in and out" in a couple hours if it was all prepped correctly. It was a good little sideline biz, increasing regulations put an end to it "we need to see engineering on that rack, or you need to buy an engineered rack and attach it to your un-engineered rack." That did it for me, I'm out! Mine had nothing not needed, most of the homebuilt racks I see are way overbuilt and very "busy," lots of pieces..., but most work just fine, no need for store bought unless you need it engineered.
