49819Re: [bolger] Re: Rudder Problems/Request design or help with Gypsy rudder
- Jun 11 9:43 AMI made stainless steel fittings for kevlar rope to anchor mines with. The fittings were cones tapered inside and out there was a bail on the big end of the cone that was made of 3/8 insquare stainless bent into a horseshoe shape and welded to the cone. The kevlar rope was put into the cone and the end frayed out. The cone was poured full of epoxy. I saw the pull testing on 10 of these assemblies. The were pulled at 30,000 lbs. the rope stretched from 5/8 in dia to 5/16 in diameter. I had thought the epoxy would fail. It all held together. Then they were pulled until failure, the bails on the fittings failed, they stretched and broke. We took bets on what would fail and I bet the epoxy would shatter inside the cone and lost my five bucks. So any way, under enough strain the kevlar stretches about 100 % . I doubt that on any small boat there is likely to be that kind of pressure even with a fairly small edge hitting the boat at 6 knots. I would think the epoxy would fail that's in the kevlar allowing water to come through. If so there would need to be a way to reseal the fabric after impact. Doug
----- Original Message -----
From: Tim Rohrer
Sent: Sunday, June 11, 2006 8:44 AM
Subject: [bolger] Re: Rudder Problems/Request design or help with Gypsy rudder
If I understand your description, this is pretty much what I'm trying. I'm building straps to go
around the cheek pieces and blocks and intend to screw them in even though they are tight.
I'm considering running bolts through where I can.
--- In email@example.com, "William " <sdavis@...> wrote:
> I had similar problems with the rudder on my gypsy having 2 failures.
> to correct the problem I made the cheek piece from 1/2" ply wood verses
> the plans 1/4" and put small through bolts through the cheek pieces
> and blocks. I used 3/16" by 1" aluminum strap bent into an L bracket
> about 4" long on both the rudder and transom with a 1/4" bronze rod
> through the assembly with 1" on each end threaded with nylon locking
> nuts on each end. since I made these changes, 2 years ago, I have not
> had any trouble with it and I do love to sail her!
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