[Rhodes22-list] Pictures and details

[sprocket80 at mail.com]

Bill,

   That is some pretty stout looking rubber hose.  I thought (without looking at a boat on a trailer) the idea was to use a softer 
hose so it can crush up some longitudinally when the boat is on the trailer' and the weight of the boat on the keel roller pushes the c/b up into the keel?  I thought the c/b rises up into the keel when on the trailer or on blocks, and this is one of the reasons for the pin/slot design...but I may be wrong.

Todd T.

 

 


 

 

-----Original Message-----
From: BillyDoc <cushman at cox.net>
To: rhodes22-list at rhodes22.org
Sent: Sun, Oct 24, 2010 11:53 am
Subject: [Rhodes22-list]  Pictures and details




I got the centerboard back in the boat yesterday, but still have the

furniture to install today.  I just wanted to get this post up ASAP with

some pictures, in case they may help someone.



When I pulled the centerboard I discovered that the blocks on the trailing

edge had pulled out at some previous time and been re-installed roughly an

inch lower.  The blocks used were not of the best quality, and I didn't like

the installation method very much either (number 8 SS bolt with locking nut,

about 1/4" from edge) as it looked like it would eventually pull out as

well.  So I fabricated a set of strain plates and installed them on either

side of the centerboard using eight 1/2" #6 stainless sheet-metal screws

each side.  The plates were fabricated from 316 Stainless, and are 0.030"

thick.  The plates were drilled with 1/4" holes to accept 1/4" x 1/2" clevis

pins for the upgraded blocks shown in the picture:

http://PoiesisResearch.com/Plates.png.  The older damaged areas were then

filled in with epoxy putty and sanded smooth.



I also wanted to reduce the vertical axis rotational slop at the centerboard

pin, so I fabricated the pin shown in the picture (in Anne's hand, also 316

stainless steel) with bearing sleeves made from UHMW-PE as shown.  These

bearings are set on shoulders machined into the pin and are 1/2" long

axially.  The shoulders were polished to make a hard bearing surface, and

the external diameter of the bearings forms a snug but not tight fit at the

bottom of the centerboard trunk slot.  The centerboard is free to slide

laterally on the pin.



After measuring my slots, etc., I thought a slightly larger than 5/8" I.D.

hose could be used without binding anything and went shopping at my local

rubber goods supplier’s shop.  I found a Goodyear product (HORIZON tm 3/4"

(19.1 mm) 200 PSI W.P) with an external diameter of about 1.125" that looked

good and bought a couple of feet of it to try.  My slots are tapered both

fore and aft and laterally, so this hose is tighter near the pivot pin than

higher up, which is a nice design feature as it will keep the board centered

in the trunk while the resistance to lateral movement will increase as the

lateral movement traveling arc increases the contact area in the tapered

area.



Two pieces of hose were cut just long enough so the bottoms touched the

UHMW-PE bearings, and the tops become constrained when the centerboard trunk

cap is put back in place.  Picture here:

http://PoiesisResearch.com/Hoses.png.  The hoses were simply jammed into the

slots from above.



We won't get a chance to try this system out this weekend, and since the

boat is on a trailer I can't check the play of the centerboard until we get

it back in the water . . . hopefully next weekend.  If I didn't

inadvertently tangle up the pendant inside the trunk or leave areas unsealed

on the trunk cap I expect the "new" system to work well!  I'll post results

after we get some testing done, hopefully next weekend.



Bill









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