Troubleshooting a rounding-up problem

[vkmaynard]

Got rid of round up by bottoming out the forestay then tuning our rig.

That's a bit vague.
I assume you man shortened your forestay as much as possible. Mine is as short as it can be, and it is VERY difficult to attach, meaning there's no way of shortening it more.

As for tuning, that's what we've been discussing. A properly raked mast should have about 4 degrees of rake. That puts the masthead about 24" off from the foot. My mast is within an inch of that.

Now I'm working on the shrouds.

Here are the specifics. See vkmaynard.
viewtopic.php?t=7926#top

Nothing vague in that post.

Victor

[Jimmyt]

Here is a post from a thread on mast setup a few years back that may have relevancy.

viewtopic.php?p=355383#p355383

Roger wanted the boats set up on the safe side. If a novice gets overzealous, a roundup is safer than a knockdown. A lot of folks have adjusted the mast rake below the recommendations in the manual, Victor being one of them. All part of fine tuning your boat.

Also note that the setup angle in the thread I’m referencing, is between the surface of the deck and the mast - not the waterline.

[DaveC426913]

Here is a post from a thread on mast setup a few years back that may have relevancy.

viewtopic.php?p=355383#p355383

IThat’s after adjusting the forestay for mast rake, of course.

How does one adjust the forestay?
My only options are physically shortening it (and everything attached to it) or moving the attachment point up the mast, neither of which I would do lightly.

And note that the 4 deg angle is from the deck, not from the center of the earth.

That is new. I thought it was from true horizontal. That's quite a discrepancy that I'd like to resolve before doing anything.

There are tension numbers out there that can be used with a Loos gauge, but I can’t find my notes anywhere. They’re out there (here) somewhere, though.

I have a document from someone on the Facebook Mac Group. I think it's from the Mac setup guide. It says "there is little to be gained by tensioning more than 200lbs".

[Dougiestyle]

Page 12 in the 26X manual. download it in the resource section on this website.

[DaveC426913]

Page 12 in the 26X manual. download it in the resource section on this website.

Thanks. That method runs counter to what we've been discussing.

Let's look at them side-by-side:

There are two discrepancies here:

• measurement from deck vs. waterline
• measurement of total mast vs. only foot of mast (i.e. not accounting for mast bend)

In the first case, the deck is certainly tilted from horizontal. This means that '4 degrees from the waterline' (our method) will necessarily be more raked than '4 degrees from the deck' (Roger's method):


In the second case, 'the total mast set to 4 degrees' (our method) is definitely more raked than 'the mast foot set to 4 degrees' (Roger's method):


This suggests that the settings were are using (in red) actually produce more rake than Rogers settings (in green).

But more rake equals more rounding up, which is safer. We are producing too much rake with our setup, causing us to round up too frequently - even more than Rogers' caution. Can any one shed light on why we would do this, or where my logic has failed?

[Jimmyt]

We have actually plowed this field before…

viewtopic.php?p=360771#p360771

To answer your questions: your logic looks correct. 4 degrees from true vertical is likely too much mast rake. Why would we do it? Because our boat was not set up properly according to the manual; either due to misinterpretation of the manual, poor measurement of a replacement forestay, excessive beer intake during setup, etc. 94 degrees from the deck is not the same as 4 degrees rake aft. Using the halyard plumb bob should probably only show a degree or two (see Be Free’s post in the linked thread). Wakataka was set up like you are and said he greatly reduced his roundup issues by reducing his rake.

If you have a furler, or your forestay is too long, this will be a bit of a pain. But, getting it right can make a big difference.

[DaveC426913]

If you have a furler, or your forestay is too long, this will be a bit of a pain. But, getting it right can make a big difference.

My forestay is very difficult to secure. I dread the idea of making it tighter. (Although there could be other causes/solutions that I don't know about).

[Jimmyt]

My forestay is very difficult to secure. I dread the idea of making it tighter. (Although there could be other causes/solutions that I don't know about).

You will be loosening the shrouds and backstay when you tighten the forestay. You don’t have to make the rig any tighter (harder to pin).

Typically, you would set the forestay up first to get the mast rake correct. Then, tension the shrouds next.

[DaveC426913]

My forestay is very difficult to secure. I dread the idea of making it tighter. (Although there could be other causes/solutions that I don't know about).

You will be loosening the shrouds and backstay when you tighten the forestay. You don’t have to make the rig any tighter (harder to pin).

Typically, you would set the forestay up first to get the mast rake correct. Then, tension the shrouds next.

Yes. I think my days of leaving the shrouds at full tension when stepping/unstepping are over. It worked for a while but obvs it's causing more head aches.

At least now that I have turnbuckles, easing off the shrouds before stepping the mast will be less awkward.

[DaveC426913]

Hadn't thought of this. Can the vang be used effectively to modify rake and thus rounding up?

I mean, yes I harden the vang to flatten the sail and depower it but is there more to it?

[Be Free]

The vang can only pull the mast aft (if at all). If it can do anything it can only give more mast rake.