A 31mm long prototype part with 6mm diameter in one end and 3mm at the other. From an M12 stainless steel threaded rod (the only stainless at hand...)
Jari machined these steel fin moulds for the PIKANTO over the weekend. The fin will be moulded with a clear glecoat, one 200g carbon layer as a surface layer, and one 250g/m2 UHM UD carbon layer. We are going to use either cnc-machined balsa cores, or a 2-component epoxy foam core. The bulb attaches with an M3 threaded rod which will be moulded into the lower end of the fin. At the boat end we'll insert a metal piece with M4 threads so the fin can be attached to the boat with an M4 hex screw.
Jari made this steel bulb over the weekend. It has a slightly triangular cross section in the beginning which flattens out to a 'beaver-tail' at the end.