Is the unistrut more ridged than the 1-1/2" square extrusion
or is it more of a cost issue?
80/20 extrusion can be purchased in 20' lengths
the unistrut would allow for a wider rail guide tho
I'd prefer for the wider bearing surface -- worst case I'd probably be alright with the 1515 extrusion mounted on unistrut (I'd like 10+ feet of rail, so that'll work), but I don't want the rail buttons to be overloaded (this rocket will be 150 lbs+ on the pad). I hate it when that happens