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Mast Anti-Rotation Device Slams Badly, Chews Up Line!
http://www.hobie.com/au/en/forums/viewtopic.php?f=13&t=13164		 Page 1 of 2
Author:  OldSalt [ Tue Jul 21, 2009 7:44 pm ]
Post subject:  Mast Anti-Rotation Device Slams Badly, Chews Up Line!
:? I have been sailing my latest Hobie 18 for only a couple of years and have noticed that the Mast Rotator limiter really slams as I sail. Secondly, even though I am using pretty expensive line on the limiter, due to the repeated slams (which have in fact pulled the jam cleat in the jib loose more than once) I am lucky to get a couple of sails in before the line is shredded.

Lastly, due to the velocity of the movement of the rotator limiter, the jam cleat won't really hold, so I end up having to put a big ugly knot after the jam cleat. :cry:

Solutions would be greatly appreciated as I will be taking a 4 day cruise (yep, will be living on or off of the tramp) down the Chesapeake Bay in a couple of weeks.

<b>THANKS!</b>
Author:  Tom Machette [ Tue Jul 21, 2009 8:03 pm ]
Post subject:  Re: Mast Anti-Rotation Device Slams Badly, Chews Up Line!
What are you doing that makes it slam like that? jibing?
Author:  OldSalt [ Wed Jul 22, 2009 6:46 am ]
Post subject:  Re: Mast Anti-Rotation Device Slams Badly, Chews Up Line!
Nope, it slams every time I come about...don't have to gibe.
Author:  ncmbm [ Wed Jul 22, 2009 7:22 am ]
Post subject:  Re: Mast Anti-Rotation Device Slams Badly, Chews Up Line!
I'm so confused! The rotator arm is slamming into what? What line is getting shredded? What does the jib cam have to do with the rotation controls?
Author:  srm [ Wed Jul 22, 2009 9:11 am ]
Post subject:  Re: Mast Anti-Rotation Device Slams Badly, Chews Up Line!
Rough water and light wind are usually the conditions that cause the mast (and whole boat) to slam around. Are these the conditions you usually sail in?

Also, just having the mainsheet loose can allow the mast to rotate freely. The forward pull of the mainsheet is what helps to hold the mast & boom in a locked position when it's tensioned.

You could try setting up a boom vang or a positive mast rotation inducer. Both of these are essentially heavy bungee cords that help keep the mast rotated to one side.

Also, check to make sure you've got an aluminum clam cleat for your rotation line, not a plastic cleat. The plastic cleats slip, aluminum do not.

sm
Author:  OldSalt [ Wed Jul 22, 2009 10:05 am ]
Post subject:  Re: Mast Anti-Rotation Device Slams Badly, Chews Up Line!
On my "Main Sail" I have the old style wishbone (with a small block at the end) anti-rotation device device. The line from the boom to the wishbone small block goes from the locked end on the boom to the small block and then goes into the forward boom jam cleat.

The "slam" comes into play when the winds are light and there is some wave action/wakes present. What seems to cause the "slam" is that there is nothing to keep the rotation device all the way out (the block and cam only hold the wishbone from going to far.

I like the idea of using a bungee to hold the wishbone under tension. Please provide pictures or (dummy proof) instructions---I am direction challenged so the simpler and exact the directions are the more likely I can follow them.

Once I have directions, I will send a pix of what I think the bungee location and tension should be so that folks can critique it before I put on the final bungees.

Thanks Again!
Author:  ncmbm [ Wed Jul 22, 2009 10:16 am ]
Post subject:  Re: Mast Anti-Rotation Device Slams Badly, Chews Up Line!
OK,I get it. I always hated that rotator set-up. I replaced it on both boats as soon as it bent.
Author:  OldSalt [ Wed Jul 22, 2009 7:32 pm ]
Post subject:  Re: Mast Anti-Rotation Device Slams Badly, Chews Up Line!
Is there an alternate anti-rotation device which actually keeps the tension between itself and the boom?

If yes, where can I get one and how much (est.) do they cost?
Author:  Skipshot [ Wed Jul 22, 2009 10:46 pm ]
Post subject:  Re: Mast Anti-Rotation Device Slams Badly, Chews Up Line!
Do you have modern low profile main blocks? If so, hang the upper block from an outside hanger on the boom, then when you sheet in you also put tension on the mast rotator.
Author:  OldSalt [ Thu Jul 23, 2009 5:40 am ]
Post subject:  Re: Mast Anti-Rotation Device Slams Badly, Chews Up Line!
Yes, I do have the low profile 8/1 Harken setup. I'll give your idea a try also!
Author:  srm [ Thu Jul 23, 2009 9:19 am ]
Post subject:  Re: Mast Anti-Rotation Device Slams Badly, Chews Up Line!
OldSalt wrote:
Yes, I do have the low profile 8/1 Harken setup. I'll give your idea a try also!



Moving the top block back would for sure be your easiest option and may very well solve your problem. Or even just running with the mainsheet a little tighter may do the trick. If you do move the main blocks back on the boom, you will have to angle your cleat down a few clicks to compensate for the change in block angle. Otherwise you'll have to reach way up to cleat the mainsheet.

sm
Author:  OldSalt [ Thu Jul 23, 2009 5:05 pm ]
Post subject:  Re: Mast Anti-Rotation Device Slams Badly, Chews Up Line!
A poster on another Hobie board suggested running a continuous line (like you do for the jib) up to a swivel block mounted on the anti-rotation arm, and then use a cam cleat on each side of the boat to tighten or loosen the arm.

Anybody know where the blocks are mounted for that sort of arrangement?

Thanks!
Author:  MUST5429 [ Thu Jul 23, 2009 5:13 pm ]
Post subject:  Re: Mast Anti-Rotation Device Slams Badly, Chews Up Line!
OldSalt wrote:
A poster on another Hobie board suggested running a continuous line (like you do for the jib) up to a swivel block mounted on the anti-rotation arm, and then use a cam cleat on each side of the boat to tighten or loosen the arm.

Anybody know where the blocks are mounted for that sort of arrangement?

Thanks!


REALLY BAD IDEA ! ! ! ! ! ! !
DO NOT use Cleats ! ! ! ! !

For one thing they are not class legal if you were to want to race, but more importantly, when you tack, if you forget to uncleat the sail shape gets REALLY Ugly and you ARE going to forget once in a while.
If you are going to do something like that, use Bungee that can run back and forth while providing tension to keep the mast from flopping around.
I am internet challenged and even if I had a picture, I doubt if I could get it posted. Maybe someone has a picture of the current setup that the racers use AND the internet savvy to post it for you to look at.

Stephen

Stephen
Author:  Tom Machette [ Thu Jul 23, 2009 8:57 pm ]
Post subject:  Re: Mast Anti-Rotation Device Slams Badly, Chews Up Line!
I tried and failed :(

Go here it is explained in the comments for the individual pictures

The positive rotation system goes from the bridals makes a loop through the mast rotator and the pipe that keeps the rotator from hitting the boom, and then back to the other bridal via bungee.
Author:  OldSalt [ Fri Jul 24, 2009 6:33 am ]
Post subject:  Re: Mast Anti-Rotation Device Slams Badly, Chews Up Line!
:D The pictures are great!

Now I have something I can copy. Once I get everything hooked up, I will send you some pix to see how well I have (or haven't, LOL) been able to follow the original.
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