Single Line Reefing vs the 26M's rotating mast

[Hardcrab]

This talk of the "slug caused gap at the mast" does make sense for air leakage from the high pressure side to the low pressure side.
One continuous run, without a gap, has to be better for power, rotating mast or not.

I think I'll tape some tell tails in the area to see how hard they may "sucked" through the slug created slot, if at all.
I'm not sure of a "fix", other than going back to the bolt rope, but That's Not An Option for me, IHMO.

Any thoughts?

[magnetic]

Let me get this right - and if you ever needed proof that a little knowledge is a dangerous thing, here it is -

are you suggesting that the mast can be deliberately rotated - i.e. not just left to it's own evil devices, but actually controlled by wilful direction from the cockpit?

I have sailed the about half a dozen times now, and the mast either does or does not rotate itself largely of it's own volition (depending upon which tack I'm on), or in response to a fairly enthusiastic "grab it & twist" manoeuvre (which only sometimes works!).

I sense I may be mikssing something quite fundamental here; looked at the other way around, I suspect that I might be about to learn something quite important - please Guys, enlighten my ignorance .....

and while I'm down there, grovelling on my belly in the dust and eating humble pie & all, could someone please give me a quick heads-up on the Slugs malarky: are we primarily talking "getting the sail up and down easily" here, or is it more "getting it to flake neatly rather than just slewing all over the place"

yours abjectly

Andrew

[Hardcrab]

Magnetic, for me the answer is yes to both up /down easier, and the "slewing all over the place" issue on dropping.
The sail is always in the track, a good thing.
If you don't have slugs, at least get a mast slot installed "feeder" to ease the job of raising the bolt rope.

And yes, people have set up blocks on the stanchions with lines running to the mast base to have positive control of mast rotation.
As I recall, it doesn't hurt or help to any big degree.
Perhaps if you are in a heavy wind area results could be better.

[magnetic]

Many thanks; I am scrabbling around trying to find a UK supplier of the slugs and have sent out emails with photos and size specs to about half a dozen chandlers (and also the UK Mac distributor).

[Highlander]

Andrew

If the mast does not rotate after a tack just pull back on the mainsheet "do not release it" and the mast will then rotate no problem

I beleive Leon & Terry have a easy set-up that can controll the amount of rotation of the mast to their desired degee of rotation

J

[magnetic]

Hi John

that was more or less where I was at - now that the vang is slightly less vice-like, the mast does seem to have a degree of in-built intuition, although I am intrigued by the idea of control lines.

In terms of overall rig tension, my lower shrouds are noticably less taught than the uppers/outers; is this typical / desirable?

A

ps the weekend out here starts tonight and 3 of us are planning to cirumnavigate The World on Saturday afternoon; if I ever get to figure out the embedding tags, I'll post a photo, but the previous owner Nevil did it twice quite succesfully and without incident. Just goes to show how fast a can sail!

[parrothead]

I've found that the rotating mast definitely helps performance, and that it's nice to be able to set it where you want it, when you want it there [especially when tacking or jibing in light air]. See other thread http://www.macgregorsailors.com/forum/v ... 00#p177113

[c130king]

My technique is if it doesn't rotate then grab the sheets (between the blocks) and give it a good yank & shake. Or grab the end of the boom if I can and pull it in and then relesae so it "bangs" back into position. If that doesn't cause it to auto rotate then if the winds are light I climb up on deck and rotate by hand...if winds are brisk then I don't worry about it and sail with it rotated the wrong way. Didn't seem to effect my performance that much...at least not enough to worry about.

It used to rotate all the time (okay 94.669% of the time) but during my Xmas sailing I decided to tighten up the aft shrouds. Took most of the sag out of the furler but the rotation percentage dropped to 71.836%. So I will take Mike Inmons advice and grease up those mast rotation washers as soon as I figure out what/where they are...never looked for them before so never noticed before.

Cheers,
Jim

[ALX357]

You responders who insist the rotating mast does improve performance .... please clarify and specify whether that is with slugs or just the luff-rope in the groove. I suspect the only improvement noted with the rotating mast is on boats that do not have slugs.

[delevi]

I have slugs and the rusults posted were with slugs. The first year I had the boat, I didn't have slugs. I noticed no loss in performance after getting slugs installed on the stock sail and subsequently had my new sail ordered with slugs. More good info on mast rotation on another thread originaly posted by Mike Inmon.

Leon

[c130king]

I have slugs but I cannot state how much of a performance boost I get from the rotating mast. I do know that over Christmas holiday I sailed on a starboard tack for probably 20 minutes with full sails, 15-20 degrees of heel, 5-6 mph average speed...with the mast rotated (stuck) the wrong way. My daughter was down below eating lunch. Didn't want to get up and rotate by hand in those conditions. Maybe I could have gotten another .5 mph...wasn't racing...wasn't too worried about this.

Here is video proof Sailing with backward mast rotation

It is time to lube up my rotating mechanism...never been lubed before. It is getting a little bit stickier because I tightened up the aft shrouds a little bit over Christmas to take some sag out of the furler.

Cheers,
Jim

[magnetic]

Just back from my weekend of dabbling about and have learned a lot - maybe just preferences, but also some basic rig mechanics -

1. Original point: led flat on the deck, whipped by F0 winds, ruler in hand, I am absolutely certain beyond any vestige of doubt that I cannot expect the mast to rotate itself if I tighten the single reef lines. There is simply no way that a taught line coming off the boom and onto the mast can maintain a constant radius to a fixed point on the deck. If the mast rotates, then the length of the reefing line would need to vary as the boom moves through an arc (it can't vary!), because the centre of rotation of the Harken swivel block is offset from the centre of rotation of the mast by about 4 inches; as the mast rotates, the only way the radius can be kept constant is if the boom remains absolutley aligned dead-centre with the mast (which clearly isn't going to happen). The second the boom is not fore-aft aligned with the section of the rotating mast, the two arcs diverge and either the length of line needs to change, or rotation can't occur. The same is true of the Vang, btw.

2. Either my Vang was installed upside down, or installing it upside down (if that is what I have now done) is a vast improvement. I now have the camcleat at the foot of the mast with the Vang line coming out towards the deck; there is a neat hole through the block which allows the line to be fed back up and made off near the gooseneck. The minute I tried to pin that line in place to a fixed point on the deck via a swivel block on the mast foot, the mast refused to rotate (see above). However, although my dreams of controlling it from the cockpit appear to have been shattered, I do now at least have a useful vang set-up, which has changed the shape of the main quite wonderfully

3. The drum on the roller furler has a remarkably sharp lip; combine this with the vertical momentum behind a hand-lifted furler, and if you go sticking your fingers in there (e.g. to unravel a tangle in the furling line) your days as a concert violinist will be limited.

4. I cannot imagine what mechanical advantage would be required to force the mast to rotate when the sail is under any significant pressure; if it rotates of it's own volition, all well and good - and I think the idea of using the sheets and the boom to encourage it is sound - but the prospect of having lines coming off of the tang at the base of the mast (where the vang attaches) is to my mind a non-starter, as the lateral forces on the deck blocks could be excessive.

My conclusion - and this is entirely down to personal preferences - is that rotating the mast is a nice luxury, if it can be persuaded to cooperate, and may yield a bit of extra performance. However, as per the video showing the "backed" mast, not having it rotate correctly in a F3-4 is not the end of the world, and at wind speeds less than that getting up on the coachroof and pleading with it is a viable (if demeaning) proposition. In contrast, getting those single reef lines led back from the mast is an absolute priority for me, and given the other clutter coming off the mast, there is no way that either the jib halyard or the vang are being led back to the cockpit any time soon, nor is there any way that I will be installing lines and blocks to forcibly rotate the mast.

In summary, therefore, in my world reefing wins out over attempts to deliberatly control mast rotation, and everything else has been relegated to being left on the mast. And the roller furler can jam all it wants - I'm not going back inside there again!

As one of my Indian colleagues recently remarked - "You may think I know b0gger nothing, but actually I know b0gger all!"

Andrew, Dubai

[c130king]

1. Original point: led flat on the deck, whipped by F0 winds, ruler in hand, I am absolutely certain beyond any vestige of doubt that I cannot expect the mast to rotate itself if I tighten the single reef lines. There is simply no way that a taught line coming off the boom and onto the mast can maintain a constant radius to a fixed point on the deck. If the mast rotates, then the length of the reefing line would need to vary as the boom moves through an arc (it can't vary!), because the centre of rotation of the Harken swivel block is offset from the centre of rotation of the mast by about 4 inches; as the mast rotates, the only way the radius can be kept constant is if the boom remains absolutley aligned dead-centre with the mast (which clearly isn't going to happen). The second the boom is not fore-aft aligned with the section of the rotating mast, the two arcs diverge and either the length of line needs to change, or rotation can't occur. The same is true of the Vang, btw.

Don't know about all that but my single-line reef does not affect the automatic mast rotation at all. I think the thing to remember is the force of rotational moment can probably pull the reefing lines just a little bit tighter than the skipper can. I crank down my reefing line as hard as I can...but there is still some room for travel especially at the clew end of the reefing system. Plus the line can probably stretch just a little. When I am reefed that means the winds are relatively stronger and that wind will force the sail/boom to rotate my mast with no problems.

2. Either my Vang was installed upside down, or installing it upside down (if that is what I have now done) is a vast improvement. I now have the camcleat at the foot of the mast with the Vang line coming out towards the deck; there is a neat hole through the block which allows the line to be fed back up and made off near the gooseneck. The minute I tried to pin that line in place to a fixed point on the deck via a swivel block on the mast foot, the mast refused to rotate (see above). However, although my dreams of controlling it from the cockpit appear to have been shattered, I do now at least have a useful vang set-up, which has changed the shape of the main quite wonderfully

My vang is also installed "upside down". The camcleat is at the bottom...this was the way the PO showed me how to set it up and I never questioned it and I have never changed it...although I don't think it would be a big deal to do so. The bitter end of the vang line line comes back to about the forward edge of the companion way opening so I just lean forward and give it a yank. And pulled as tight as I can possibly pull it the vang does not effect mast rotation.

3. The drum on the roller furler has a remarkably sharp lip; combine this with the vertical momentum behind a hand-lifted furler, and if you go sticking your fingers in there (e.g. to unravel a tangle in the furling line) your days as a concert violinist will be limited.

Agree. Must keep some tension on the furling line when letting the Genoa out and must keep some tension on the sheets when furling the Genoa...this will keep the the furling line from "bird nesting" inside the furler drum.

4. I cannot imagine what mechanical advantage would be required to force the mast to rotate when the sail is under any significant pressure; if it rotates of it's own volition, all well and good - and I think the idea of using the sheets and the boom to encourage it is sound - but the prospect of having lines coming off of the tang at the base of the mast (where the vang attaches) is to my mind a non-starter, as the lateral forces on the deck blocks could be excessive.

Agree. Not worth the trouble, extra lines coming back to the cockpit, nor lines to trip on going forward. I think once I grease up my washers I will have no big issues with rotation. For Leon and others that have much tighter rigs then they have to deal with this issue...if they choose to. Personally if it becomes that much of an issue I think I would just pin the mast straight.

[Highlander]

Here's how to run jib & main halyard lines aft cleated at the base of the mast on these swivel cleats mounted on the mast
http://i235.photobucket.com/albums/ee20 ... 0012-1.jpg

As for fingers I just bought another one of these puppies Harken 00AL
http://i235.photobucket.com/albums/ee20 ... 0026-1.jpg
so now I'll have matching furlers & sell off the mac furler
http://i235.photobucket.com/albums/ee20 ... 0021-1.jpg

J

[magnetic]

John, as ever, many thanks for all of this. The tag line in my previous posting says it all - I am on a learning curve here, and I think that for many of us personal preference probably wins out over technical excellence

all the best

Andrew