Getting the shoulder to rotate about it axis was not a problem. Finding the parts to keep the shoulder together and to do it remotely was another story. I had a .060 base plate machined to support the fiberglass and then had a custom laser gear and sprocket made to fit the 23″ Rockler bearing and Banebot motor. All of this was experimental. I didnt know if it would work but I thought I would give it a try. Turns out it work out pretty good.
The other problem I had to overcome was the air pockets i was encountering on the edges of the shoulder. Basically, craters had formed where air had been trapped during the gelcoat to fiberglass application process. We used the short, chopped strand fiberglass and the high quality fiberglass resin but this shoulder did have a lot of those air pockets. So I drilled them out and filled them with EverCoat body filler RAGE and then used the Evercoat Polyester finishing putty for a glass smooth surface. A lot of work but it was worth it.