I thought I'd share the new improved system for building a MUCH stronger pinwheel.
This cross is made with .6mm copper.
It's harder to build the antenna with this but it's worth it. Cutting this small piece is very difficult even with a cnc. As it's hard to hold the copper sheet to be cut.
The SWR does not change at all, but the cross does shift the center frequency up by 20mhz on 1.2 ghz. antennas, as it effectively shortens the lower arms. So I have to readjust the dimensions of the legs by 1 or 2 mm.
The result is a much sturdier antenna as you can see.