Vang attachment problem

Moderator: GreenLake

Re: Vang attachment problem

Postby GreenLake » Fri May 30, 2014 3:30 pm

K.C. Walker wrote:Maybe you could sleeve your sleeve and attach it to that.


A full doubling up would seem a bit overdone, perhaps. Attaching to the sleeve would still put upward load on the deck, as the sleeve can slide relative to the mast, but would transfer horizontal loads nicely to the mast. Because of geometry, those are the stronger ones.
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Re: Vang attachment problem

Postby K.C. Walker » Fri May 30, 2014 9:19 pm

When I was setting up my vang it's a 5:1 with a double cascade. I tried it as 5:1 and I really couldn't get any mast bend to speak of. At 10:1 I could get mast bend but it took a fair amount of effort. At 20:1 it really does not feel like much effort. I would guess that 20 pounds would be the max and probably not even pulling that much. The effort doesn't seem to change from the "on" setting to the "fully on" setting. I would guess that 20:1 is more than is needed but I just went with what the racing guys use. I know that it has evolved over time from a lesser ratio to what seems to be the preferred standard of 20:1 now. It does work nicely.

Mike Gillum says that he was mangling the sliding gooseneck on his boat so he went to a more secure Thistle style set up. I thought that I would do the same but have not noticed any problems with the sliding gooseneck after multiple seasons of use. If I've got it hard on and don't release it when tacking sometimes it does flop to the other side and make a very disconcerting noise (like something broke in the standing rigging).
KC Walker, DS 1 #7002
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Re: Vang attachment problem

Postby UncleJohn » Sat May 31, 2014 2:48 am

GL -

That's quite the mast-stepping attachment you have there...

Earlier, on my vang thread, I suggested a U-bolt through the deck. Now that I've seen your set-up ... I still think that might be the best approach.

Threading an extra long bail bolt through the whole contraption seems like it might be kind of fiddly - and each extra step at launch time starts to add up. Plus, the bolt or pin holding the bail would need to be quite long and rather stout. That would mean a pretty big hole in the mast - not a good thing. And what about the sideways forces? Would the bail slide from side to side on alternate tacks and crush your mast-step basket?

Other options... Mount the bail to the hinged base plate? You say it's sturdy and should be able to take the stress. Or, what about the lower section of the mast? Could you run the vang down through the cuddy opening and attach it to the bottom of the mast or to the keelson just aft of the mast? That might work on my DS1, but probably not if you have a DS2 with a small cuddy opening.

- John
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Re: Vang attachment problem

Postby GreenLake » Sat May 31, 2014 3:43 am

John, the base plate that you can see in the picture is 1/8" aluminum. Bolting a padeye style fairlead right in front of the mast and running a spectra loop is possible. Other than re-engineering the hinge to get rid of the sleeve (or basket as you cal it) to free up the front of the mast, or drilling for a cross bolt, all solutions discussed so far end up with putting an upward load on the deck. I'm confident that I can solve any issues of local stress, the base-plate arrangement with its plywood backing plate is sufficient.

Leaves the question whether a deck that can handle 2-300 lbs crew weight during rigging will stand the same force when applied up not down. K.C.'s estimate is reassuring in that he's not maxing out that 20:1 :shock: -- in fact what he reports is below the reverse of crew weight, leaving a reserve for peak loads (sudden gusts).

The through bolt approach has the advantage of simplicity and completeness (just the bolt and the bail), but the downside is that I'd have to assemble it each time - my efforts in general go towards reducing the effort for setting up.

During the season, for example, my jib-sheet stays rigged as shown
1545
the light green is a soft shackle tied with a Prusik knot to the sheet. Even though the shackle is slippery Amsteel and the sheet also has a rather slippery cover, the knot has never moved since I tied it. With this setup, I simply connect the clew.

A similar shackle,or even a spliced loop could be used with a padeye, and be left in place to attach the vang. Amsteel is super-easy to splice... if experience shows too much "give" in the deck, there was the suggestion to rig what amounts to a reverse compression post. Simply a strong strap connecting deck and keelson. (Except, I have a mast-jack on my DS1, so I could not run anything close to the mast base, or I can't turn the bronze nut that raises the mast to tension the rig.)

Several people have reported here that they built a sturdy frame connecting the rear lip of the cuddy to the floor, to stiffen the boat. So, that is something I could consider making part of the overall design. (As much as I hate encumbering the cuddy opening).

It occurred to me that the bolt & bail setup might be improved if I could fit a bit of aluminum tube connecting the holes on the side of the mast, so as to provide a guide for a bolt. That would take the element of "fishing for the opposite hole" out of the equation...

So, back to the drawing board.

Anyway, thanks to everyone who generously contributed suggestions.
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Re: Vang attachment problem

Postby TIM WEBB » Sat May 31, 2014 3:51 pm

K.C. Walker wrote:Mike Gillum says that he was mangling the sliding gooseneck on his boat so he went to a more secure Thistle style set up. I thought that I would do the same but have not noticed any problems with the sliding gooseneck after multiple seasons of use. If I've got it hard on and don't release it when tacking sometimes it does flop to the other side and make a very disconcerting noise (like something broke in the standing rigging).


Had the same issue after I installed a vang. Replaced the "open" U-joint pieces of the gooseneck with a solid piece of SS with two holes drilled through it 90 degrees apart.

My vang attachment is a 3" bail on the rear hinge pin, with one of these riding on it, and the cascade portion running through that:

http://www.duckworksbbs.com/hardware/bl ... /index.htm (the 307-A)

1781

Sounds like that's not an option for you GL, so I vote for the hole through the sleeve and mast. The aluminum tube guide is a great idea.
Tim Webb
1979 DS2 10099 The Red Witch
(I used to be Her "staff", in the way dogs have owners and cats have staff, but alas no longer ... <pout>)
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Re: Vang attachment problem

Postby seandwyer » Tue Jun 03, 2014 11:24 am

GL,

I've read through the responses to this rather quickly, so perhaps this suggestion has already been made, but what if you replaced the lowest bolt currently running through the rear edges of the metal and wooden part of the guide with a longer, SS bolt that has been threaded on both ends and has holes drilled through the ends as well. Run the bolt through, screw nuts from either side to tighten, then fasten a small piece of cable (about the size of the standard ball ended vang cable attachment at the boom) through the holes effectively creating a cable type padeye. I suppose you could come up with connectors to fasten over the ends of the bolt to be held in place with more nuts and not bother with drilling holes in the bolt, too. Or, if you don't mind drilling another hole through your mast raising device, you could find some purpose made stainless pin with eyes at either end that can be run through and cabled at either end.

Hope this makes sense.
Sean
DS1 - 3203
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Re: Vang attachment problem

Postby GreenLake » Tue Jun 03, 2014 1:32 pm

Sean, your suggestion is to fix a bail to the base of the contraption. Cable is interesting, but a normal U-bail (stirrup shape) would presumably work. I could replace the pin in the hinge with a bolt like you suggest and then use that as the bar for the U-bail. It's a variant of a "deck mounted" attachment, one that is in the traditional location behind the mast. Incorporating it in the hinge is a new idea, but, as you point out, drilling through the wooden block is another variant.

I'm going out today to have a friend help me look over the boat for some other modifications I am planning and he's promised to help me evaluate the feasibility of various schemes discussed here.
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