[Rhodes22-list] Pictures and details

Mon Oct 25 19:15:27 EDT 2010

Hi Bill,

It may be interesting to note that this is a problem that was addressed by 
Stan in the original design of the centerboard.  Probably before yours was 
modified by a previous owner, the lift points on the centerboard were not 
fancy blocks but rather fixed stainless tubes between pieces of medium duty 
stainless plates that were attached to the board (through bolted pairs of 
plates.)  The plates were probably Dwyer DH 72-5 Shroud Tangs (5" x 1" x 
5/64").  Nothing rolled but the line slid on the fixed tubes well.  Due to 
the duty cycle, abrasion was not an issue.  I never worry about the block 
being off-center and hitting the cap or jamming since it is fixed.

I wish I had a photo.

Mike
s/v Shanghai'd Summer ('81)
Nissequogue River, NY

From: "BillyDoc" Sunday, October 24, 2010 2:31 PM
>
> Ouch! I wish I had thought of that before putting in those fifty bolts. 
> You
> are exactly right, of course.  The next time I have it apart I will
> definitely de-articulate the blocks with some epoxy putty.
>
> Thanks for pointing that little problem out!
>
>
>
> Geankoplis wrote:
>>
>> Hi Bill,
>> Nicely done.  Well engineered, well thought out and great detailed
>> information on materials.  There is one concern.  Having owned a couple 
>> of
>> Rhodes for  pretty much the last 34 years there is a potential problem
>> that
>> I ran into. This involved an articulated rather than a fixed block.  On
>> the
>> off chance you run aground the articulated block without the tension of
>> the
>> pennant will flop sideways and will probably jamb in the centerboard 
>> trunk
>> or without the plates simply  break off a bit of the trailing fiberglass
>> edge of the centerboard. It happened to me twice before I figured it out.
>> Next time you go into the centerboard you may consider fixing the blocks
>> so
>> they can't move left or right, er, port and starboard matey.  Hope this
>> helps.
>> Chris Geankoplis
>>
>> -----Original Message-----
>> From: rhodes22-list-bounces at rhodes22.org
>> [mailto:rhodes22-list-bounces at rhodes22.org] On Behalf Of BillyDoc
>> Sent: Sunday, October 24, 2010 8:53 AM
>> To: rhodes22-list at rhodes22.org
>> 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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>> Sent from the Rhodes 22 mailing list archive at Nabble.com.
>>
>>
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>>
>
> -- 
> View this message in context: 
> http://old.nabble.com/Loose-centerboard-tp30013496p30042541.html
> Sent from the Rhodes 22 mailing list archive at Nabble.com.
>
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