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Thread: Getting Ready for SHTP 2021

  1. #111
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    Sep 2007
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    PTFE tubing...

    https://fluorostore.com/products/ptf...aghetti-tubing

    I got size 8, ID of 0.12 to 0.14 inches, standard wall.
    The weed whacker monofilament is .08 inches thick ....that should fit. I got ten feet, just in case this happens to be SO slick that I can go back to the full-length cable/housing setup that I originally wanted.
    S-2 7.9: "Wildcat of Loch Awe"
    1968 Selmer Series 9 B-flat and A clarinets
    1962Buesher "Aristocrat" tenor saxophone
    Piper One Design 24, Hull #35; "Alpha"

  2. #112
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    I went down to the boat yesterday to check the fit on the companionway cover from the Santana 3030, that I adapted. Nailed it.

    ....though this is one of those jobs that serves the function, and looks good from 20 feet away, but don't get too close. Next up, get some 1/8th plywood and make the hatch scabbard, which will be in front of this cover.

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    I will need to replace the companionway board-retaining boards, to allow the companionway boards to be pulled out. The cover "leans back" a bit at the aft end, which limits the movement of the boards, coming out. This is fine, I've been meaning to replace them with aluminum ones, anyway.

    Finally the cover is out of my front yard! sheesh...it's been WEEKS.
    Last edited by AlanH; 05-04-2020 at 11:24 AM.
    S-2 7.9: "Wildcat of Loch Awe"
    1968 Selmer Series 9 B-flat and A clarinets
    1962Buesher "Aristocrat" tenor saxophone
    Piper One Design 24, Hull #35; "Alpha"

  3. #113
    Join Date
    Jul 2016
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    Bodfish, CA
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    Quote Originally Posted by AlanH View Post
    Well, I took the contraption down to the Port, where there was a solid 15+ knots of wind oscillating through about 15-20 degrees. I'm sad to say, that the brake cable linkage friction almost completely prevented the system from functioning at all. It would "move"...when the blade was practically perpendicular to the wind, if you waited 10, 20 seconds for it to finally slip and GO. The wind vane itself is phenomenal. It's extremely sensitive and I think significantly more powerful than the old vane on my Naviks. However, the cable friction...no.

    Not acceptable. OK, so that's the end of experimentation with the bicycle brake cables. Now I have extra cables and housing for my bike. **eyeroll**

    I was down there from 1:00 - 2:00

    Attachment 5368

    This iteration of the linkage uses half the cable housing of what I had originally concocted, but that wasn't enough. I was right in guesstimating the amount I wanted, to allow for rotating the vane though 360 degrees without binding the cables, but it didn't matter.

    Attachment 5369

    Next up...PTFE cable housing liberally sprized with Tri-Flow teflon, with .080 in wede-whacker monofilament running in it. There are two, 6 foot bits of it hanging on 15 pound weights in my garage right now, to "assist" them in "forgetting" the tightness of the spool they were sold in.
    Aha! This entire assembly seems to act as a wind steered trim tab. What happens with the tiller? Is it locked in a neutral position?

    The trim tab would have to have some well balanced sails.

    Onward.....

    Ants

  4. #114
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    Quote Originally Posted by AntsUiga View Post
    Aha! This entire assembly seems to act as a wind steered trim tab. What happens with the tiller? Is it locked in a neutral position?

    The trim tab would have to have some well balanced sails.

    Onward.....

    Ants
    No, Ants, it's not a trim tab. It's a pendulum oar, but the way it acts on the rudder is completely different from how a more "usual" pendulum oar system, like a Monitor, works. A "usual" pendulum oar system is mounted on a framework on the back of the boat. The mast that holds the actual wind blade can be on the centerline, or slightly off from the centerline...or even quite a bit off from the centerline, but the pendulum oar is on the centerline (usually!...). In the usual configuration, the rotation of the pendulum oar is transferred to the tiller through low-stretch control lines.

    In this vane, the pendulum oar is mounted on the head of the rudder, in a hinge, and it swings, just like a usual pendulum oar. However the pendulum oar is locked in place with lines to the stern quarters. It can still turn under direction of the wind blade, so that it gets pushed to an angle off from the direction of water flow, and generate a sideways force, but it doesn't swing. The geometry of Jan Alkemas system transfers the sideways force directly to the top of the rudder, causing it to turn, via that hinge mounting. There are no lines in the cockpit.

    You have to read Jan's paper, and stare at it for a while for it to make sense...
    S-2 7.9: "Wildcat of Loch Awe"
    1968 Selmer Series 9 B-flat and A clarinets
    1962Buesher "Aristocrat" tenor saxophone
    Piper One Design 24, Hull #35; "Alpha"

  5. #115
    Join Date
    May 2009
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    247

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    That looks great!

    Quote Originally Posted by AlanH View Post
    I went down to the boat yesterday to check the fit on the companionway cover from the Santana 3030, that I adapted. Nailed it.

    ....though this is one of those jobs that serves the function, and looks good from 20 feet away, but don't get too close. Next up, get some 1/8th plywood and make the hatch scabbard, which will be in front of this cover.

    Name:  CompCover1.JPG
Views: 214
Size:  236.2 KB

    Name:  CompCover2.JPG
Views: 238
Size:  221.9 KB

  6. #116
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    Aug 2009
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    Quote Originally Posted by AlanH View Post
    I'm working from home and it's just not that busy. Also, now I have more weekends free. Joan wants to go hiking a lot, which is good but I still have time to make "boat stuff". In light of that, I'm starting on the next project, which I didn't think I would get to for months....a windvane.

    I'm going to be making a variant on Jan Alkema's USD windvane, combined with his RHM pendulum. Mister Vee uses the USD concept, (USD = UpSide Down) but I don't know of any commercial enterprise that makes a RHM pendulum. "RHM" stands for Rudder Head Mount, and it's a servo-pendulum specifically designed for transom-mounted rudders. You can read about the system here: http://www.windautopilot.de/docs/alkema/RHM-USD.pdf

    Jans own prototype, which he used on a boat not THAT different from the Wildcat, was a plywood job, though he changed over to welded stainless after a few years. I'm building ver. 1.0 in redwood and fiberglass/epoxy. Today I cut out the redwood bits for the actual mount and would have cut out the parts for the oar, but I ran out of time.
    I've been enjoying the progress! I have never been on a boat with a windvane and only vaguely understand the mechanics and was also wondering if it is a trim tab. I went back to look for the paper, fig 5 helps. It's complex and I hope you keep posting your results! I think: Vane pivots in the wind, cables make pendulum oar pivot on its pintles, this makes oar pivot on point P held by line, so the rudder head moves opposite the oar blade, and since the head has moved it also has turned the rudder? Is that close??
    -Mike

  7. #117
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    You got it, Mike!
    S-2 7.9: "Wildcat of Loch Awe"
    1968 Selmer Series 9 B-flat and A clarinets
    1962Buesher "Aristocrat" tenor saxophone
    Piper One Design 24, Hull #35; "Alpha"

  8. #118
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    Hey, electronics cognoscenti....

    Lookie here.

    See the compass on the starboard cockpit bulkhead? Now...see the plastic panel below that, which covers up a very old bulkhead cutout? If I put my depth sounder readout in that plastic panel, will that wreak havoc with my compass?
    S-2 7.9: "Wildcat of Loch Awe"
    1968 Selmer Series 9 B-flat and A clarinets
    1962Buesher "Aristocrat" tenor saxophone
    Piper One Design 24, Hull #35; "Alpha"

  9. #119
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    Sep 2007
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    395

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    Quote Originally Posted by AlanH View Post
    If I put my depth sounder readout in that plastic panel, will that wreak havoc with my compass?
    That will entirely depend upon the depth sounder readout display. Can you tell us what you're planning to put in the cutout?

    On the other hand, if you treat an SSS TransPacific race boat as an Italian sports car, the first thing you should do upon starting is rip out the depth sounder and toss it overboard behind you - where you're going the sounder won't measure depth! (Italian sports car drivers do this to their rear view mirrors - at the speed they are traveling the only interesting thing is in front, never behind).

    Could the compass be moved to port side into the other cutout?

    - rob/beetle

  10. #120
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    Quote Originally Posted by tiger beetle View Post
    That will entirely depend upon the depth sounder readout display. Can you tell us what you're planning to put in the cutout?

    On the other hand, if you treat an SSS TransPacific race boat as an Italian sports car, the first thing you should do upon starting is rip out the depth sounder and toss it overboard behind you - where you're going the sounder won't measure depth! (Italian sports car drivers do this to their rear view mirrors - at the speed they are traveling the only interesting thing is in front, never behind).

    Could the compass be moved to port side into the other cutout?

    - rob/beetle
    It's a RayMarine i40 Dept readout which happens to be....rectangular.

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    I know, right? As soon as I'm past Point Bonita, who needs a depth sounder? But the SSS "outside the gate" racing rules say you must have a depth sounder, so I bought one...quite a while ago....and I'm going to get around to installing it here, pretty soon.

    Yeah, I could move the compass, but my laptop and the AIS receiver were...in theory....going to live not far from there. However, the compass sort of ~has to~ work, so....
    S-2 7.9: "Wildcat of Loch Awe"
    1968 Selmer Series 9 B-flat and A clarinets
    1962Buesher "Aristocrat" tenor saxophone
    Piper One Design 24, Hull #35; "Alpha"

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