Elane, Here is my DIY bimini project:
Bimini Top for around $200; I started with a standard 3-bow 30” H x 67” W bimini from coversearch.com
The next step was to replace the tower cap screws with ones 1 1/2” long (3/8-16). Leaving nearly 1/2” of exposed threads.
I then took threaded 3/8-16 standoffs and brazed 1/4 -20 nuts to the standoffs.
I bolted the standoff / nut configuration to the exposed tower screws and measured the distance in between.
After assembling the largest of the bimini frames to determine the difference in the widths that would need to be made up, I disassembled the frame and used a 3/4” conduit bender to equally de-arch each side until it was a the correct width.
It was then necessary to do the same for the remaining 2 frames in order to meet the width of the slide-jaw mounts on the main bimini frame.
After re-assembling the bimini I found that the front frame was too wide so using a tubing cutter I narrowed it by 3” taking 1 1/2 ” from each side of the cross piece.