G'day guys, Thanks very much for the positive feedback.
I had her out again today in skinny water this time. i think the problem was just that my lifting cord is a little big in diametre and the friction of it running through my plastic tube guides was enough to stop it going all the way down.
It has freed up a lot and is working perfectly now,
Do you think that, (1) a light bungee to hold the rudder down may work?
Yes, but I am trying to avoid it if I can.
(2) the mount and pivot would benefit from beefing up a bit?
I don't think so. The mount is 3/16 X 3/4", 316 grade stainless steel and is held in place by two 1/4" 316 grade stainless bolts that were epoxied into the stern of the boat when I built her. There is a significant end pour of epoxy & wood flour holding the heads in place inside the boat. I think the mount and the mounting set up is stronger than the rest of the boat.
When I build another blade, it will be of 4mm (5/32"?) Gaboon, BS1088 ply, and feather it into a proper hydrofoil shape. That should take care of any weight problems and still not cause too much drag in the water.
The timber steering pivot block I made is from a single piece of machined iron bark. one of the tensionally strongest hard woods we have. I laminated 4mm ply to either side of the machined strip with epoxy/wood flour and then filleted every where I could to re-inforce it. I tried to make allowance for the thing getting a pretty rough ride on the roof of my car.
A couple more piccies. (not relevant to the build but I think they are kinda nice.) I took them from Southwind this morning.
Cool, frosty morning on my local lake.
Coupla spectators.
