Saturday, August 28, 2010

Back to Boatwork

I've got a few projects on the table before I can get sailing again. With the collapse of my mainfoil in Harbor Springs I need to resurrect my original mainfoil I built in the fall of '07 with Gui's guidance. The foil is a bit fat by today's standards but does work. It will be mated to a strut I built last spring from John Z's mold. The strut is pretty strong (maple core) but a bit shorter than the current trends. I've decided that the pair will not be separable - I'll glue and carbon the tee-joint to try to git it a bit more strength. I'll also have to layup a well section and build a new cassette to fit the boat. My top end adjustable feature is working fine so I should be able to tweak the AoA and find the best position after a few sails. There will undoubtably be some tweaks to the bell crank and pushrod. I'll be using a 2.5 mm FC pushrod that broke at the bottom end but will be long enough for my shorter strut. I'll have to dig out the tapped barrel in the flap and re-tap to the larger size (I had been using 1/8" pushrod.)   The ultimate long term goal after saving lots of pennies will be to fit a new production strut and mainfoil from one of the professional builders.

I'm also finishing off a new gantry (my third.)  My existing gantry is kludged together after failing in the Gorge. The "agricultural repair" (as Bear put it) has held up, but I'd like to loose the aluminum plate and the through bolts. The new gantry keeps the forward cant of the rudder but should be lighter and stronger. It is also cleaner, without the bottle screw and fairing of my existing gantry. 

Lastly, I'm tweaking the rack's front end. To make the rack system able to be taken apart I had included a sleeve and throughbolt on one side. There has developed some wear and play which caused me to lose rig tension during the course of a sail. The beefed up rack should be able to take the rig and hiking loads without shifting.

My goal is to have everything done by mid September. There is a long distance race that weekend that I'd like to sail in and then the HHPDO in October.  Of course, everything will have to be fit in around school since it's back in session now.  Pics to follow in future posts.

1 comment:

johnz said...

Good idea on the not-separable plan. I think the carbon fillet at the joint is pretty to look at but vulnerable to peeling off. The fun part in building carbon parts is in planning loads to be in tension or compression and avoiding "peeling" situations. My thought (after heavy input from Bill B) was to switch to G10 cores on the vertical and horizontal near the joint and add two 1/4-20x2" flat head machine screws from the bottom up. It is essentially a butt joint and the carbon sides of the vertical handle compression loads and the machine screws handle tension. I do have fillets but think they are mostly for looks since I PVA'd my joint on assembly so that I could add shims when needed.

I probably don't sail my boat as hard as you but have a good 50 hours on it without any strut or foil failures. Ain't light but keeps me on the water instead of in the shop!