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Forestay too long (false alarm)?

Posted: Mon Apr 25, 2016 5:41 am
by Neo
New mast and new forestay (in the Furler) but it seems to be too long.
I have tighten the turnbuckle all the way up but it won't pull the mast vertical. ... I'm guessing it might be 1 to 2 inches too long.

The upper shroud bracket might be too low .... does anyone know the amount of inches from the base it supposed to be?

I could try putting the shackle bolt through the forestay thimble but I'm not keen on that solution.

Any thoughts?

All the best.
Neo

Re: Forestay too long?

Posted: Mon Apr 25, 2016 9:11 am
by Tomfoolery
The mast is supposed to have some rake to it, though I don't know how much for an :macm: . Have you checked the manual, which has dimensions to check for mast rake (page 11)?

Edit: On mine, there's more than 6" of forestay length difference between vertical and the recommended 4 degrees of rake. Just so's you know. :wink:

Re: Forestay too long?

Posted: Mon Apr 25, 2016 4:09 pm
by Neo
I can't find any information on how high up the upper shroud bracket is supposed to be on the mast .... Does anyone have/know this?

Many thanks.
Neo

Re: Forestay too long?

Posted: Mon Apr 25, 2016 4:41 pm
by NiceAft
Neo wrote:New mast and new forestay (in the Furler) but it seems to be too long.
I have tighten the turnbuckle all the way up but it won't pull the mast vertical. ... I'm guessing it might be 1 to 2 inches too long.

The upper shroud bracket might be too low .... does anyone know the amount of inches from the base it supposed to be?

I could try putting the shackle bolt through the forestay thimble but I'm not keen on that solution.

Any thoughts?

All the best.
Neo
See comments on your “worst nightmare” posting.

Ray

Re: Forestay too long?

Posted: Mon Apr 25, 2016 5:23 pm
by RobertB
For the dimensions, go to the resources tab above, and check page 11 on the manual for the M. The 156 inch dimension is what you need.

Re: Forestay too long?

Posted: Mon Apr 25, 2016 5:44 pm
by Neo
No that's actually the Mast raising attachment point/boom bail ... But I'm referring to the mounting (bolt) point of the upper shroud bracket .... some 350" up the mast.

I'm also thinking that the Forestay was made incorrectly (or Macgregore made them in different lengths throughout the years?) ... I can't lower the mast right now but will compare the forestay with the old one when I can.

Ray, the Mast is currently being held up by the MRS and is 1" aft of the vertical line.... but the Forestay is very slack even at 1" back.

Re: Forestay too long?

Posted: Mon Apr 25, 2016 7:11 pm
by Tomfoolery
Neo wrote:Ray, the Mast is currently being held up by the MRS and is 1" aft of the vertical line.... but the Forestay is very slack even at 1" back.
The 4 degrees of rake of the :macx: mast translates to almost 2 ft back at the top of the 28 ft of mast, which is a lot for a saiboat. Again, you need to use the 156" dimension on page 11 to determine the correct angle of rake for the mast on your :macm: . The forestay may not be too long. Or it may. Can't tell from here. :|

Re: Forestay too long?

Posted: Mon Apr 25, 2016 7:24 pm
by Neo
Thanks for clarifying of that (again) Tom ... Will measure it up and come back to you guys

Re: Forestay too long?

Posted: Mon Apr 25, 2016 7:28 pm
by Tomfoolery
The :macx: rake is measured directly as an angle between the mast and the deck immediately in front of it (94 degrees), but the :macm: is measured as a diagonal between some point on the mast and some point on the bow, at the rub rail. And I have no idea what the resulting angle is. But that's how they're specifying it. :wink:

Re: Forestay too long?

Posted: Mon Apr 25, 2016 8:41 pm
by RobertB
The angle of the mast is not easily something you can measure due to the contour of the deck - I ran all the geometry when rigging a new forestay and furler last year. There is no obvious surface to measure to. The only data point to use is the 156 inch one - and the associated side stay measurements.

Re: Forestay too long?

Posted: Mon Apr 25, 2016 9:23 pm
by Neo
Wow what a dramatic diffrance that has made up 156" line and secured it at both ends. Then gradually loosened the turnbuckle while gradually adjusting the stays.
Turns out the Forestay is not too long .... it's too short!! :o

I think a 2nd 8mm shackle (or an extra long one) should solve that problem ... or what about using an anchor swivel?

Thanks for your help so far guys :)
Neo

Re: Forestay too long?

Posted: Mon Apr 25, 2016 9:37 pm
by RobertB
I redesigned so I could use a Johnson lever - great mod that makes rigging much easier and puts less pressure on the deck from the mast raiser - I crushed my deck at the daggerboard. Do you have about 8 inches to make this mod?

Re: Forestay too long?

Posted: Mon Apr 25, 2016 9:42 pm
by Neo
RobertB wrote:Do you have about 8 inches to make this mod?
Hmmm... I don't think so but will only known as I keep letting it out..... Nice suggestion though ... maybe in a few years when I get a new forestay made up. :)

Re: Forestay too long?

Posted: Mon Apr 25, 2016 11:52 pm
by Highlander
Neo wrote:
RobertB wrote:Do you have about 8 inches to make this mod?
Hmmm... I don't think so but will only known as I keep letting it out..... Nice suggestion though ... maybe in a few years when I get a new forestay made up. :)

U do not need to buy a new forestay just raise ur masthound !! :)

J :wink:

Re: Forestay too long (now to short)?

Posted: Tue Apr 26, 2016 7:35 am
by RobertB
I needed to make a new forestay because I had that that Mac-Special-custom-built-with-half-the-parts-and-features-without-any-adjustment roller furler. The Johnson lever was secondary - but worth it. All told, I did install a second mast hound because I needed to use the stock sail.