Friday, August 24, 2012
I fabricated the cassette using the rudder foil as a mold. The first step was to wrap the finished rudder in 6 mill plastic with a couple of wraps to provide decent clearance between the cassette and the foil. I then used the same CF sleeving that I used to create the rudder foil for the inside and outside layers of the cassette, with layers of uni-directional carbon fiber in the middle layers. Once the epoxy set, I then glued on some "stand-offs" to hold some G10 (fiberglass) tubing in front of the leading edge of the rudder cassette. The tubing has a 3/8" inside diameter and is intended to hold the stainless steel pin. Once the epoxy was dry, I faired the area around the tube to insure a nice smooth finish and then wrapped 4" wide unidirectional strips of CF around the G10 tube. One point is that I used a single length of tubing along the leading edge of the cassette so that I didn't have to worry about aligning different sections of tube. I later cut off the tube sections that I didn't want. The picture above shows the cassette before I trimmed it to length. It also shows the "handle" which will attache to the tiller. The handle was fabricated using a piece of ordinary pink insulating foam from Home Depot. I turned the foam on a lathe to get the shape that I wanted (a slight taper from back to front). I then wrapped the foam with release cloth, then layers of CF (sleeves and uni) and then wrapped that in release cloth. Once everything hardened, I removed most of the foam using a 1" hole spade (flat drill bit). Using some needle-nosed pliers I took out the inside layer of release cloth, by just grabbing a corner of the cloth and twisting. After taking off the outside layer of release cloth and then cutting a U-shaped channel in the handle, I then epoxied it onto the cassette. I did drill a hole from the top of the handle to allow the rudder pin to be inserted from the top.