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Re: [campernicholson] Rudder Angle

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  • O. R. Armstrong
    Colin, Actually, once I devised the puller with the threaded rods, it was quite simple. Some of the messages indicated that it had taken days to get those
    Message 1 of 13 , Oct 18, 2011
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      Colin,

        Actually, once I devised the "puller" with the threaded rods, it was quite simple. Some of the messages indicated that it had taken days to get those flanges off. With the improvised puller, it only took hours.

        Not sure what the sealant bedding my flange might have been. It was very rubbery; the yard thought it was Sikaflex. If it had been 3M 5200, I would have to have used dynamite.

        I agree that Simon's pintle was a quality job. Really good pictures, too. Maybe I'll put up some to show how I did it, because it sounds harder than it was.

        I am considering drilling a half-inch hole in the upper trailing edge of the rudder, sealing the interior edge with resin. In the event of a catastrophic failure of the rudder, I could pass a rope through that hole and up to some blocks in order to steer. I'd expect never to use it, but it would really look "salty," eh?

        Russ Armstrong


      On Tue, Oct 18, 2011 at 2:09 AM, <colin@...> wrote:
       

      That sounds like one hell of a job! I am dreading taking it on myself this winter although i think that the top rudder bearing on Trutz is bedded down on a non adhesive sealant. Maybe it will be easier?

      The job that Simon had done on Blue Nava looks 'Rolls Royce' in terms of quality of material and workmanship.

      The hole(s) in the top of the pintle were for threads of glass to be passed through to sort of tie down the pintle in its correct location with matting and resin glassed over the top. Simons solution is a good one and the addotion of some short tangs either side would make it even better.

      There have been some innovative rudder rebuild jobs done it seems. We will go for the bullet/bomb proof solution when we have the rudder off as it is a job i only want to do once. We will gel strip the rudder too, build back up with new mat, epoxy then coppercoat.


      Colin Campbell-Dunlop
      Azure Consulting
      68 King William Street
      London EC4N 7DZ
      +44 20 7193 4232
      www.azure-consulting.com


      From: "O. R. Armstrong" <russ.armstrong@...>
      Date: Mon, 17 Oct 2011 22:42:14 -0400
      Subject: Re: [campernicholson] Rudder Angle

       

      Hi Colin,

        As noted, the rudder travel available on my boat, lock to lock, is 55 degrees; 27 -1/2 degrees each side. The designed rudder travel, lock to lock, was 70 degrees; 35 degrees each side. I'm not sure how many degrees the Garmin autopilot will want to use at any given time. I expect that it may sometimes want to go all the way to lock, perhaps when doing a tack. I'd like for it (and especially the helmsman) to have the full 35 degrees as designed. Lower hull numbers have the prop on the back of the fin, and it is not very effective at using propwash against the rudder for docking, as the prop is not close enough. A few extra degrees of rudder angle might help a bit.

        My quadrant stops are simply pieces of stainless angle, held to the underside of the cockpit sole with a single bolt. Once I get the measurements, it shouldn't be too difficult to re-position them. Of course, I've made similar statements about other projects . . .

        I'm taking the rudder, key and quadrant to a machine shop tomorrow. The key is worn and there's about 1/4 inch of play at the end of the quadrant.

        Regarding the pintle, per your suggestion, I searched the forum messages, and there were a number of postings about the pintles working their way up into the interior of the rudder. There is an excellent photo showing how to remove the pintle in the Photo section of the forum at Blue Nava rudder rebuild photo gallery. Photo 7 looks like they welded a hole saw to a piece of pipe. Photo 9 shows the old and new pintles. I understand the grooves in the new pintle, but what are the holes for? Are there set screws?

        In the messages in the forum, I noticed comments that it was difficult to remove the lower flange of the two-flange packing gland, which is glued to the hull with Sikaflex. On my boat, the upper flange was also extremely hard to move. Hammering and prying got no place. There are threaded studs that are screwed into the lower flange, which pass through holes in the upper flange, topped by nuts. They hold the two flanges together. I removed them (which involved a Sawz-All). I bought two 18-inch ordinary threaded rods, 1/2 inch in diameter, at the local hardware store. I had the boat yard drill two 9/16 holes in a small (say 4 x 5 inch) piece of 1/4 inch steel. Through the emergency tiller access hole, I dropped the threaded rods down through the holes in the upper flange, and put nuts and washers on the underside. Up top, I lowered the steel plate over the threaded rods, using a large socket as a spacer between the steel plate and the top of the rudder shaft. I tightened the nuts (keeping the threaded rods from twisting with vise-grips) until the flange came up some distance. I then dropped the rudder enough to get the quadrant off the top of the shaft. Then I tightened the nuts on the threaded rods the rest of the way, pulling that flange off the top of the shaft. I removed the threaded rods and the plate.

        Back to the lower flange, still stuck to the hull. I removed the cut-off remnant of one stud, and drilled out the other one from the emergency tiller access hole with a long 3/8" drill bit. I had also bought 3/8 threaded rods at the hardware store. I repeated the process as above, except this time, I had to pry against the bottom of the cockpit, rather than the top of the shaft. I put 4x4 wooden blocks on the cockpit sole either side of the pedestal, and bridged them with a 2x2 piece of oak. The steel plate bore against that. Again, I tightened the nuts at the top of the rods, holding the rods with vise-grips, and up came that flange. Once loose, I could move the lower flange and rudder shaft aft, enabling the rudder to drop without binding on the skeg. Archimedes had some good ideas.

         Russ Armstrong

      On Mon, Oct 17, 2011 at 3:08 PM, <colin@...> wrote:
       

      Hi Russ,

      Agreed, there is more travel available lock to lock but the pilot doesnt really need it. 25 degrees each side is plenty.

      Ref the movement in the pintle. Problems with the bottom pintle are well documented on here. It seems to work loose and disappear up inside the rudder. We are having our rudder out this winter and that is a key area that i will be looking at. My sense is that there shouldnt be any movement in the pintle. If there is we will have to do the job. It is quite an involved job taking it all apart so only doing it once would be a good idea.



      Rgds

      Colin

      Colin Campbell-Dunlop
      Azure Consulting
      68 King William Street
      London EC4N 7DZ
      +44 20 7193 4232
      www.azure-consulting.com


      From: "O. R. Armstrong" <russ.armstrong@...>
      Date: Mon, 17 Oct 2011 14:14:48 -0400
      Subject: Re: [campernicholson] Rudder Angle

       

      Colin,

        At first, I thought what what you suggested; that the numbers in the table in the Garmin instructions were "lock to lock." 36 - 38 - 40 - 42 - 44 - 46 - 48 -50. But then I checked the drawings in the back of the original CN35 user manual, and they showed amidships to hard over, either way, as 35 degrees (70 degrees lock to lock). They also showed the location of the quadrant stops being slightly forward of an athwartships line drawn through the center of the rudder shaft. By contrast, my quadrant stops are exactly on that line.

        I have the rudder out, getting a new key made for the quadrant to take out a little slop. I'll put the rudder back in without the quadrant to see a 35 degree rudder angle causes the leading edge of the rudder to impinge upon the hollowed trailing edge of the skeg.

        While I'm on the subject, my pintle has about a 16th of an inch of vertical play, but nothing side to side. Is that normal?

        Russ Armstrong

      On Mon, Oct 17, 2011 at 8:56 AM, <colin@...> wrote:
       

      Hi Russ, we have just put a Raymarine pilot on Trutz mated up to the original (but adapted) Neco motor and teleflex drive.

      From the guy setting it up i seem to recall amidships to hard over either way was 25 degrees. Total from hard over port to hard over starboard being 50 degrees obviously.

      Maybe your Garmin is 36 degrees 'lock to lock'?

      Rgds

      Colin

      Colin Campbell-Dunlop
      Azure Consulting
      68 King William Street
      London EC4N 7DZ
      +44 20 7193 4232
      www.azure-consulting.com


      From: "Russ" <russ.armstrong@...>
      Date: Mon, 17 Oct 2011 12:43:06 -0000
      Subject: [campernicholson] Rudder Angle

       

      I'm installing a Garmin autopilot in my 1974 CN35, hull #99. It uses a Jeffa linear drive. Installation requires determining the "rudder angle" - the degrees from amidships to full port or starboard, governed by the stops which limit the travel of the quadrant. My rudder moves only 27 - 1/2 degrees, while the smallest rudder angle listed on the reference table in the Garmin instructions is 36 degrees. Hm? I expect my helm would be noticeably more responsive with an extra 7 - 1/2 degrees of rudder travel!

      I consulted the original printed user manual, which has several fold-out pages in the back, one of which is a diagram of the steering system. There it states and shows that the rudder angle is 35 degrees. The location of the quadrant stops in that drawing is different than on my boat (obviously).

      A prior owner had installed an Autohelm a/p on the boat, the one with the little black gear ring on the steering wheel with the little motor attached. I'm suspecting that the stops were moved to accommodate that Autohelm. Could anyone confirm that?




      --
      "We don’t allow faster than light neutrinos in here" said the bartender. A neutrino walks into a bar.




      --
      "We don’t allow faster than light neutrinos in here" said the bartender. A neutrino walks into a bar.
    • MarkH
      I don t know about the smaller CN rudders but our 58 required a new plastic bushing on the lower pintle of the skeg. Fortunately, the top was OK. If you need
      Message 2 of 13 , Oct 24, 2011
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        I don't know about the smaller CN rudders but our 58 required a new plastic bushing on the lower pintle of the skeg. Fortunately, the top was OK.

        If you need a replacement, I suggest you look here. My lower cost 7.50. I use these guys in our machine business. The parts are tyhe real thing.

        http://www.igus.com/default.asp?PAGE=IGLIDE&WT.srch=1&WT.mc_id=gadUS49&c=US&L=en&gclid=CI-iyZ7YgqwCFZAAQAodeRPROA

        Try not ot get confused with the massive choices of options. Remember, when our boats were made, 90% of these choices did not exist. Moly filled Nylon will more than exceed any original material.
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