Das Boot

The original plan I had in mind was to build a boot.  Six planes later and I finally return to this idea.  What I learned about balsa wood construction building planes, translated well into boats.

The basic design goals for my RC sailing boat are speed, control, and stability.   I also wanted to experiment with a laminar flow hullform.  You don't see many boats with a laminar flow hull and there's probably a good reason for this in full scale boats.  However for this sized boat scaling factors make drag due to wetted surface area less of a issue.  The intended effect for the laminar flow hull to to provide roll and directional stability.

This a sailing boat so there is a keel to counter the heeling force of the sail.  The keel is comprised of balsa surrounding an metal core made up of an old 1/4in allen wrench and a 3in x1/2in diameter rod.  The keel mass was about 150grams.

Notice the strut for the hydroplane.  This also make a nice stand. It's a Popsicle with a piece of steel wire along the leading edge for rigidity.  I tempered the steel wire by heating red hot, wait ten seconds, and then dropping it into cold water.  I've determined that ten seconds makes perfect spring metal that's not too brittle.

Here is a front view of that very deep "V" hull.  Loaded to the gunnels, this hull displaces about 2lb.

Now to level the deck, so that I can have a watertight seal.  Later I'll add a plywood deck that will act as a removable servo tray and provide a mount for the sail mast.

The rudder is comprised of balsa around a bamboo core.  The top inch of the bamboo core is epoxied into a brass tube.

Another view with the rudder in place.

I build the hydrofoil around the Popsicle/steel core and the filed the top surface into a 6% thick foil.  Notice that bias of the wood on the bottom runs front to back and the bias on top is from side to side.  That makes the top surface easy to shape while the bottom strengthens the trailing edge so you make it sharp.

This project is a bit further along now but I need to take a few more picture.