Steve....How long are each roof brackets before shaping the ends and putting the
bow in? How many are needed?Did you build a bending jig to put the arch in
so they are uniform?
The bows are about 48 inches long. There are five of them.
I removed the poptop from the trailer and built a jig in my workshop to hold it upside down. The center of the jig was half an inch lower than the edges, so when I put bricks inside the top, the center portion was deflected down (upward when installed on the trailer) half an inch, and voila, there was my roof contour.
I then built one master rib, taking care to get it symmetrical and a nice tight fit against the underside of the deflected top, and then built four more using the master as a template. The ribs were not all exactly alike, so I stamped a letter into each one to keep them organized. I was able to fine-tune the lengths of the downturned ends so that they'd "snap" into place above the edge molding, which held them while I drilled the holes and bolted them into place.
Each rib is held by two 1/4 inch stainless screws at each end, with rubber sealing washers.
I was careful to leave enough space between the aft two ribs so that if Sis ever wants to replace her 9-inch vent with a bigger one (fantastic fan?) she'll have space to do it.
One problem that emerged was that since the roof is a lot stiffer, I was unable to insert the locking pins in the lift mechanisms when the top is down--I couldn't deflect it downwards enough to make the holes line up. I ended up making 1/4 inch plastic spacers to put under the upper lift mechanism brackets, spacing them downwards 1/4 inch, and now the holes line up fine.