Wheel to Tiller conversion concerns

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  • 31 Jan 2019 19:38
    Reply # 7139610 on 4286270

    I could cut off the square section, get keyways machined into the ends, and use one of these:


    It's pricey, $256 USD for 303 Stainless Steel.  But... it is kinda designed for this.

    Last modified: 31 Jan 2019 19:40 | Anonymous member
  • 31 Jan 2019 17:25
    Reply # 7139351 on 4286270

    I haven't much to offer on this, except to say that skeg-hung rudders sometimes have a joint at the point where the the stock exits the hull and joins the blade, in the form of a jaw welded to the end of the stock. Thus, the stock and its GRP tube are not compromised, in strength, integrity and maintainability.

  • 31 Jan 2019 17:02
    Reply # 7139313 on 4286270

    Len and Anthony, both of those ideas are something I hadn't considered at all.  I'm going to go and stare the pieces for a few hours with those two approaches in mind.

  • 29 Jan 2019 20:51
    Reply # 7135789 on 7134989
    Scott Dufour wrote:

    I'm chuckling, because David and Asmat's answers show how far apart considered responses can be.  And I've been wandering all over that distance for a year now.

    Ah good! You will like my idea even better. A really big socket wrench with a socket that fits the top of your current rudder shaft (square I think you said). Kidding aside, a coupling that fits that square and can couple to whatever shaft you want to use (I have put a 6 foot extension on a 3/4 drive more than once so it doesn't have to be 1.5 inch) would allow removing the rudder as can be done now. An older propshaft with keyway would go into the other end of the coupler...

    Or (best idea yet) make the extension square too and use a coupler that is two piece each with a V shaped inside with four big machine screws to hold the two sides together. It would be possible to make such a coupling with time, an angle grinder, time, a drill, time and a file. A machinist may be quicker and cheaper and more accurate. The thickness of the steel for the coupler should be 1.5 inches. The width would be 3.5 inches assuming the machine screws are 1/2 inch. The length would be the height of the square portion of the rudder shaft X two + some fudge space in between where the minimum length would be 2 inches for 1/2 inch screws. It would be ok to use 8 screws (4 on each side) with a minimum length of 4 inches... if your machinist disagrees, they are more likely right than I am.

  • 29 Jan 2019 18:47
    Reply # 7135582 on 4286270

    How about grinding down opposite sides of the squared section at the top of the existing shaft to half the shaft diameter.  Then cut a 3-inch slot in the lower end of the extension, so that the two shafts mate together.  Finally, drill two holes through the joint laterally, with small lengths of s/s rod to stop the joint pulling apart.

  • 29 Jan 2019 14:24
    Reply # 7134989 on 4286270

    I'm chuckling, because David and Asmat's answers show how far apart considered responses can be.  And I've been wandering all over that distance for a year now.

    Last modified: 29 Jan 2019 14:24 | Anonymous member
  • 29 Jan 2019 10:14
    Reply # 7134743 on 4286270

    Hello Scott,

    I decked in the after half of my K26 cockpit and had to extend the 1 1/4" stainless steel rudder stock. I used a length of scrap propeller shaft, attached using exhaust hose and hose clamps. A keyway and bronze key were needed to prevent problems caused by slippage. Trying to weld the extension on, I don't think I'd have got it truly lined up straight, and I would only have been able to drop the rudder with the boat suspended aloft.


    Last modified: 29 Jan 2019 10:28 | Anonymous member
  • 29 Jan 2019 04:07
    Reply # 7134393 on 4286270

    Hi Scott,

    my feeling is that it may be best to build a new rudder. I know it seems like a lot of work and cost but at least you would have a one piece shaft of known material (A section of old worn prop shaft can usually be obtained at very reasonable cost, with enough material clear of the wear to make a rudder shaft). Alternatively I would consider welding an extension to the existing rudder shaft. This may mean testing the existing shaft to see what it is, you suggest in an earlier post that it may be Monel. A friend in California lengthened the shaft on his 33 foot Crocker designed ketch. It was bronze but he had no problems with it once he found what the type of bronze was and found the right welder to do the welding!

    All the best with the project.


  • 28 Jan 2019 21:03
    Reply # 7133748 on 4286270

    I've purchased a 1.5" diameter, 18" extension for the rudder 1.5" diameter rudder post, plus a 12" SS tube that slip fits over it (and the existing rudder post).

    But I'm having cold feet. There are all sorts of little issues on how to stretch the rudder post, and the fact that I can't find anyone on the internet who's done it gives me pause.  

    1)  The 4" diameter fiberglass rudder tube is now glassed in place, extending about 5" above the cockpit sole, which is about 16" above the waterline.

    2) The existing rudder post top is squared off for its top 3 inches (to accept the emergency tiller), and tops off at about 6 inches above the waterline.

    3) I can't permanently attach the new rudder extension to the rudder post using the SS tube and some high strength potting material because then I'll never be able to drop the rudder for maintenance in the future.

    So I need to be able to:

    4) Permanently secure the SS tube to the extension, 

    5) Strongly and not-permanently secure the SS tube/extension combination to the rudder post

    6) Have a way to get at said attachment in the middle of the glassed-in rudder tube to un-secure it, pulling the extension out through the cockpit, and the original rudder post down through the hull for maintenance.

    The only thing I've come up with is to:

    7) cut out a section the glass rudder tube right around the join. The missing section of rudder tube can be replaced with a high strength rubber boot and hose clamps.

    8) Then, after having secured the SS tube to the extension via thickened epoxy, pack the resulting SS Tube socket with more thickened epoxy and slip the existing rudder post with it's squared top generously coated with releasing wax into the socket and let cure.

    9) Once it's all setup, drill through the SS Tube and some of the rudder post to put in several set screws.  My assumption is that the thickened epoxy working against the squared section of the rudder post will handle the rotational forces, but I need something to keep the extension/tiller from pulling the socket slowly upwards.

    I'm really not happy with this solution: it just seems like I've replaced the multiple failure modes of a wheel with multiple failure modes of a strangely coupled shaft.  Can this setup handle the tens of thousands of cycle loads it needs to?  Because it's, you know, the steering.

    Should I instead be getting a shaft extension welded on?  It's very hard to get that done right, too. 

  • 16 Apr 2018 20:00
    Reply # 6101563 on 4286270

    I'm dusting this off because I'm dropping the rudder this weekend.

    The rudder and rudder shaft are in good condition - no play, corrosion, weeping from the rudder, creaking under force, et cetera.  But of course, the rudder shaft is now about 18 inches too short.  

    To accept an emergency tiller, the top 3 inches of the shaft is machined into a square cross section with the diagonals equal to the shaft's diameter.  It's possible that it's even made of monel like most of the critical components on the boat. 

    I've got several ideas on how to extend this thing - but all of them feel uninformed and too-clever-by-half.

    What's a recommended rudder shaft stretching method?

    Last modified: 28 Jan 2019 20:32 | Anonymous member
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