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Thread: Getting Ready for SHTP 2021

  1. #101
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    I think someone did, yesterday. But I'll keep my ear to the ground if you like.

    Despite it's condition, this was one of the most frequently-sailed boats at RYC.

  2. #102
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    Quote Originally Posted by BobJ View Post
    I think someone did, yesterday. But I'll keep my ear to the ground if you like.

    Despite it's condition, this was one of the most frequently-sailed boats at RYC.
    I've looked it over, very hard more than once. The cockpit was a bit cluttered and broken up, and it had running backstays. Aside from that, it always seemed a very sensible boat, to me.

    There's no way I can convince Joan to swap boats, now....and if I DID "swap" boats, there's a Wilderness 30 on my dock that hasn't moved in two years. The lifeline gate has been clipped open for two years...nobody has even been on board in all that time. A Wilderness 30 has been on my "short list" of boats I kinda always wanted for almost 20 years. Olson 911-S...Wilderness 30...and a couple others.

    I'm committed to doing this in the Wildcat, now.
    Last edited by AlanH; 05-02-2020 at 10:09 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. #103
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    After being very grumpy all night over yesterdays FAIL, and after looking VERY hard, for quite a while at Jan's vane, I see how he gets around the problem of the changing length of the distance that the cables cover, as he changes the heading. To replicate that, I'll have to make two more large-ish pieces and a mounting bracket....all do-able of course... but it make the basic premise of the vane carrier assembly "sleeving" over the mast, irrelevant.. I rather like the notion of the whole thing sleeving over the "mast" and I want to stick with it. It's super simple and rather light-weight.

    I may have to go to a central push/pull rod linkage (I can use a carbon fiber kite rod, or some old fiberglass tent poles that I have.), linked by a bell crank to a "bent rod" actuator kind of system as per Walt Muray's work, or any of several commercial systems. THAT, I might have to do. We'll see. Before I do that, I think I'm going to spend $20 for ten feet of ptfe housing. PTFE = "Teflon" and you can buy flexible tubing made of the stuff. Running heavy monofilament (basically weed-whacker cable) though that, well slicked with Tri-Flow should be awfully slippery.

    Before that, though, I'm taking the whole thing down to the port, tomorrow, with my 8 foot ladder, a mess of clamps, some grease and a pair of cable cutters. I will set the whole thing up in the closest geometric alignment to how it will actually be on the boat, and we'll see if changing the amount of cable housing and the amount of curvature of the cable, cuts the friction, substantially. It might not....or it might. We'll just see, tomorrow.
    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"

  4. #104
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    More study of Jan Alkema's setup revealed something that I hadn't realized before. It's hard to explain but what it means is that the final turn of the control lines is centered over the axis of rotation of the rudder. THAT means that from that point..the final turn of the control lines, the distance to the pendulum oar "tiller" stays constant as the rudder moves. However, if you move that final turning point off of that axis, the distance DOES change...which is something I was trying to get around with the brake cable housings.

    If I align the mast of the windvane right over the axis of rotation of the rudder, that simplifies things. It also means that today, I reduced the amount of brake cable...and brake cable housing by half. There's a transition from s.s. cable to a piece of inexpensive polypro line right now. I'll change that over to light dyneema, if this all works out. This has helped with the friction issue. So has grinding the ends of the housing totally flat and reaming them out to make SURE there are no burrs or protrusions to rub against the cable.

    I might be at a point where a good breeze and a larger wind paddle could make this work.
    Last edited by AlanH; 05-03-2020 at 12:01 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"

  5. #105
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    Did you grease the cables too?

  6. #106
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    Quote Originally Posted by Intermission View Post
    Did you grease the cables too?
    You bet...good old waterproof Phil Woods green stuff...and it made it WORSE...MORE friction. So I wiped it off and shot more TriFlow down in the housing and soaked the cable with it really well. The more I move it around, the smoother it gets, BTW.
    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"

  7. #107
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    Quote Originally Posted by AlanH View Post
    You bet...good old waterproof Phil Woods green stuff...and it made it WORSE...MORE friction. So I wiped it off and shot more TriFlow down in the housing and soaked the cable with it really well. The more I move it around, the smoother it gets, BTW.
    I have a long Phil Wood story that I typed up here once, but then lost somehow.

    What time will you be in RWC today?

  8. #108
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    This morning I got up and went reading about what you are constructing - that's a fascinating design, solves a problem in a clever way, and looks like it can be made to work.

    My suspicion is that you're fighting friction and mass in the build. You want the air vane to transmit small amounts of movement to the water pendulum, and any friction in the system is bad. Any loss of movement in the cabling is also bad. Bowden cables are great for some things (primarily transferring tension) but have a lot of slop and friction as compared with rigid rods or tensioned cables on pulleys. Jan's notes mentioned using ball bearing blocks and wire to move forces from the air vane to the water pendulum - that might be worth trying with thin spectra line.

    Is there any way to re-work the various bearing points (pintles, pivots) to use delrin bushings or ball bearings?

    On the mass side of things, the less mass the air vane has to move the easier it should be to move that mass. In theory the lighter the air vane is the more sensitive it becomes while the forces it can transmit remain the same. Similiarly for the water pendulum - minimizing mass would make it easier to rotate/steer.

    This is a really clever project - do keep going with the updates. As regards reducing friction, avoid high viscosity grease/oil and go with spray-on Teflon (e.g. McClube) or powdered graphite (e.g., ground up pencil lead or lock lubricant graphite). Anything to minimize viscosity, not trap dirt, and minimize friction.

    - rob/beetle

  9. #109
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    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

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    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.

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    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.
    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"

  10. #110
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    So, adding up all the bits and bobs, this "brake cable idea" is about a $50 FAIL. On the other hand, I've been nursing this idea for almost 15 years, since I attempted my first windvane in 2005 and it's good to finally know the answer!
    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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