Thursday, July 1, 2010

Getting Rid of Slop

I've dissassembled the worm gear trying to figure out where the extra play is coming from.  My best guess is that the primary culprit is the kludgy swivel shackle (a Ronstan part.)  Unfortunately, there doesn't seem to be a way to reduce the play here. I wonder what other home builders are using for the swivel... any suggestions???

Another problem has been the lower gudgeon. I'm using some G10 glass laminate with about eight layers of carbon cloth on the bottom side. The 1/4" hole drilled through this composite plate just seems to slowly enlarge. To hopefully get a bit more life (and reduced wear) I'm fastening onto the bottom of the laminated gudgeon a stainless steel plate from a old tang that has a machined 1/4" aperture. There seems to be just enough play to accommodate a few degrees of misalignment as the AoA is adjusted.

On a related note, I got some 10mm OD carbon tube from and I find that my existing wand from FC is way whippier than it needs to be. I don't know the specifics at to wall thickness and construction  (although the new tube seems just a hair thicker), but using the flex-in-the-hands test, it's appreciably stiffer. So, a new paddle on a new stiffer tube should help immensely. If things kick by this afternoon (perhaps with some heat gun assistance) I'll try it out this evening (the forecast is still calls for 10-15 kts out of the north!)


Teknologika said...

Hi Joe,

I am not using one myself, and I haven't built one either, but I guess that the more expensive, higher precision swivel would be a lot better



Joe Bousquet said...

Thanks, Bruce, for the suggestion. I'll start saving pennies...

If you don't use a swivel in your system, how do you change a hiking stick twist to a fore and aft movement of the pin?

Phil Stevenson said...

We do not use any swivel. Description of system inside tiller:
3in long Acetal plug at aft end, slide fit inside tiller, cross bored for rudder pin and drilled and tapped about 10mm at the front to accept;
a 10mm brass or nylon pin which treads into the acetal plug and is glued to a 12mm carbon tube which is as long as the tiller.
Near the front of the tiller there are three acetal rings about 12mm wide. The cetnre one is loose on the 12mm tube and neat inside the tiller, The 1st and 3rd are neat on the tube and clear of the tiller ID. The three are stacked tight together. 1 and 3 are secured to the 12mm tube with screws. #2 is secured to the tiller withh short screws after assembly is inserted in the tiller.
The three rings act as your swivel, prevent the shaft moving for and aft and also hold the tube centre in the tiller up front so the tiller extension does not wobble.
Depending on how thick your 12mm carbon tube is you might as an internal sleave at the front where the screws go.
My universal for the extension is simply 3 ply of braided rope, bound glued and screwed onto the carbon tube abd into the extension.

This is what I have used since 2005, based on a slightly different prototype designed by my son Andrew. My original used less precice components, but it was copied by AMAC for the Bladerider. It is still working on my previous boat.
Phil Stevenson

Joe Bousquet said...


Do you know if Amac is still using this system, or something similar, on his M2?


johnz said...

I'm using the same swivel as you but I beat the crap out of the pin with a punch and maul until the rivet shortened up and the slop went away. Phil's method is much more elegant. I just recently saw the guts of the Bladerider plug and it is very elegant. Now we know who to credit that to. I'll switch to something like that on my next one. - John Z