Squirrelly steering at slow speeds

Discussion in 'Downeast Boat General Discussion' started by Snake8, Mar 14, 2019 at 10:45 AM.

  1. Snake8

    Snake8 Member

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    Boat is a 32 Osmond with power assisted steering. When I am going at no wake speeds up to about 8kts if I take my hand off the wheel the boat wanders. Even if you hold the wheel straight it will wander. It doesnt seem to favor port or starboard. Once it tastes a direction it veers hard in that direction. Its so bad that if I ask someone else to grab the wheel they invariably struggle to keep her straight. Above those speeds she does OK. At this point I have adapted to the issue, but since I may be dropping the rudder this spring for a new shaft, I figured it might be worth trying to kill two birds.

    More potentially relevant info (I can get exact measurements/specs on any of these if the forum requests such data):
    - Rudder is fiberglass, when I got the boat there were several abrasions in the rudder. This is a working lobster boat, abrasions are from line running across rudder - from previous owners. I patched and filled, but the rudder is pretty worn and not square. It is more of a trapeziod with the upper part being wider.

    - The prop is about 1 1/2" inches from the cutlass bearing. The shaft was cut and shortened to change the wear spot from the stuffing box (which is why I am replacing the shaft, the old wear point is worn down about 1/16").

    - There is no slop in the rudder bearing.

    Thoughts? Recommendations? It is certainly something I can live with for now. Aside from this issue I love how the boat steers, turns almost within its own length.
     
  2. Genius

    Genius Captain

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    I believe it to be common on fiberglass rudders....that the stock will develop slop between the fiberglass. It probably could be repaired, but a better idea would be to have a stainless rudder/stock built. First thing I would do, would be to observe the steering gear while this 8kt problem is occurring. Go back there and open the steering lazaret hatch and see what is going on. If there is nothing abnormal, I bet it's the rudder stock to blade problem.

    D
     
  3. Frank

    Frank Senior Member

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    With the size of the keel on those H&H boats I'm shocked to hear of any wandering.

    "Go back there and open the steering lazaret hatch and see what is going on." Good advise from Genius.
     
  4. TCL

    TCL Senior Member

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    Could it be “bow steering “? Not usually a problem on a DE hull, more of a problem on a planning hull with a forward CG as far as I know.
     
    TCL,
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  5. Diesel Jerry

    Diesel Jerry Captain

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    Agree 100% with all of that. I would also look at how big your rudder is and possibly, if getting a new one, go a little bigger.
     
  6. Keelboater

    Keelboater Captain

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    Check the weight distribution. As TCL mentioned, it could be bow steering. If the bow is "digging in" at dead slow speed, it will wander all over the place. Bump the throttle just a bit and it goes away all together......just enough to make a no wake situation miserable for everyone at the dock. I'm trying to correct that problem on my boat now. The rudder on my boat is perfectly fine and there is no excessive slop in the steering. Granted, they're all different so I just thought I would mention this. In my case I am hoping the new light weight fuel tanks help, and I'm moving weight towards the stern. With a full keel, I don't think any D.E. boat should bow steer like this at dead slow speed. JMO.
     
  7. Snake8

    Snake8 Member

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    Hmmm, hadn't considered bow steering, engine is quite a bit forward, but from pictures underway and just the feel of the boat and no bow wake at slow speeds she doesnt seem to be to bow down, but Ill take that into consideration. Theoretically, if I loaded a few 50 gal barrels with water on the stern that should ameliorate the problem if it was bow steering? Any other way to test that hypothesis? I have had 50+ traps on the deck which definitely sinks the stern, but it doesnt stop the wandering.

    And Genius, good idea. I usually do that when I launch. The rudder seems fast to the stock, but I'll check that again.

    Wondering if it could be the hydro motor. I know when the motors go on the hauler, they start to "give back" rope.
     
  8. Keelboater

    Keelboater Captain

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    My thoughts are that if it is bow heavy to begin with, and then you load 50+ traps on the deck, the entire hull will just sink further into the water......bow and all.....even though the stern might sink more than the bow. But the water barrels can be concentrated right at the stern rather than spread across the entire deck, which might lift the bow just enough to confirm things. I am no expert at this by any means, just throwing the idea out there for you. Maybe it works, maybe it doesn't, and maybe it's not even bow steering that is the problem. If you ever get it figured out, please let me know what you found. Good luck.
     
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  9. south shore

    south shore Senior Member

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    Had this problem on a boat but with a I/O and I feel your pain, my old boat would do the no same thing. Was going to name the boat the Wanderer. Low speed going down the canal if you pull your tee shirt off over your head when you looked back up you where already going in a different direction. It was a very difficult boat around the gas dock, you could be pulling up to the gas dock and at the last second it would go right and your heading straight into the dock. Slow speed trolling was a full time job, tap the throttle to over 8 knots and it was a different boat.
    I didn't think it to be a bow steering issue as much as an issue with the bow sliding around. If I ran full tabs in the canal it was a little better. Had my brother on the boat one day and told him to take his 300lb ass and to go up and sit on the pulpit and it made a pretty big difference. After that I made 4 - 50lb tubes out of 4 inch pc pipe, concrete and old sash weights and put them up forward under the bunks. Made a 50% difference in the low speed handling and didn't notice any difference in the cruising properties of the boat. It's an annoying issue and hard to get it solved, good luck.
     
  10. Diesel Jerry

    Diesel Jerry Captain

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    I forgot about that little cheat. A lot of times I have to run small outboard and I/O boats in the marina. I put the trim tabs down all the way to help the boat handle better. I also works well with the bigger, but light inboards keel or no keel.
     
  11. Snake8

    Snake8 Member

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    Good ideas/thoughts. I checked the rudder and it seems fast to the stock.

    Any thoughts on the hydro motor being the culprit? And/or how to test it? Its your basic char-lynn/eaton and I noticed yesterday a small leak. Since those motors are relatively cheap (compared o say a new SS rudder) I might just slap a new one in there and see what that does.

    Keelboater - you may be right, Ill have to check when I am setting out in May. However I do have a stern table that is just under 3' hanging off the transom, so when I load her up there is a lot more weight in the stern, Im pretty sure it looks like this nice Holland:
     

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  12. hardcore1

    hardcore1 Captain

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    I would be curious as to the power plant, gear ratio and prop size. Also rudder size. This could be as simple as not enough thrust passing by the rudder to get good steering. Once you bump the throttle you are pushing enough water past the rudder to maintain a straight line. Could be a small rudder, small prop, or high gear ratio problem.
     
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  13. Snake8

    Snake8 Member

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    Hardcore,

    Cummins qsb 5.9 380hp, zf 2:1, 24 square. I dont think its lack of thrust unless, as mentioned before, prop is pretty far from the rudder because the shaft was cut. Ill measure the rudder if I can get down to the boat without sinking into the mud.
     
  14. Diesel Jerry

    Diesel Jerry Captain

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    Snake8 where are you located. PM if you don’t want that public.
     
  15. hardcore1

    hardcore1 Captain

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    Should be plenty of thrust. A picture of the running gear would be nice to see. The wide fiberglass rudders are definitely not streamlined like a metal one would be and will require a little more water passing by it before it will stabilize. If it is small in size switching to a larger thin stainless rudder could solve your problem.
    If the rudder is undersized, adding weight to the boat will usually only make tricky steering more pronounced
     
  16. PatriciaLynn

    PatriciaLynn Senior Member

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    Sure sounds like she is down by the head but 50 traps and a 3' stern extension ought to fix that.
     
  17. Old Mud

    Old Mud Captain

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    Did you bleed the system ? Maybe air at the ram ? or air bound at the helm ?
     
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