M31 tuning the rigging -- MOA

[ Show ]

Support VoyForums

[ Shrink ]

VoyForums Announcement: Programming and providing support for this service has been a labor of love since 1997. We are one of the few services online who values our users' privacy, and have never sold your information. We have even fought hard to defend your privacy in legal cases; however, we've done it with almost no financial support -- paying out of pocket to continue providing the service. Due to the issues imposed on us by advertisers, we also stopped hosting most ads on the forums many years ago. We hope you appreciate our efforts.

Show your support by donating any amount. (Note: We are still technically a for-profit company, so your contribution is not tax-deductible.) PayPal Acct: Feedback:

Donate to VoyForums (PayPal):

Fri, April 26 2024, 09:13 [ Login ] [ Contact Forum Admin ] [ Main index ] [ Post a new message ] [ Search | Check update time | Archives: 1, 2, 3, 4, [5], 6, 7, 8, 9 ]

[ Next Thread | Previous Thread | Next Message | Previous Message ]

Date Posted: - Tuesday - 07/ 7/09 - 3:45pm
Author: Lyle Harris
Subject: M31 tuning the rigging

6 months after pulling the masts, they've been stripped, repainted, and are back on the boat. Everything's loose, the new spreaders droop downward, and I the split back stay turnbuckles are tightened all the way down while the back stay remains floppy-loose. It's clearly time to bring in the expert rig tuner, which I'm doing at the end of the week.

any advise is welcome. I've reviewed some of the past postings about the topic, but more is better for the moment.
Lyle.

[ Next Thread | Previous Thread | Next Message | Previous Message ]

Replies:

[> rigging -- kathy Campbell M32 Shadow, - Tuesday - 07/ 7/09 - 5:38pm

Hi Lyle,
This is the voice of experence. If you get a professional rigger make sure you go over your rigging yourself. Aren't you in Brion Toss's neck of the woods, Washington? Anyway, you can get a rig tuning CD from Brion. If you called them I'm sure they could help you get things in order. After my near catastrophe - a cracked beam under the main mast - thanks to a professional rigger, every skipper needs to have some knowledge of rig tuning.
Here's Brion Toss - www.briontoss.com 1-800-488-0855
Yours truly, Kathy

[ Edit | View ]

[> Tell the rigger, not too tight -- Randall, Murre, M31, - Tuesday - 07/ 7/09 - 5:48pm

Hey Lyle,

Weird for sure!

One word of advice to the rigger is not to tighten down like he's working w/a fiberglass boat and a keel stepped mast. Most of those guys are use to cranking in until you can play a tune on the rig, and that can easily damage our deck stepped, wood framed arrangement.

Several of us have been victim to an over-eager rigger.

Have him tune to rig like it's a wooden boat.

---

Interesting situation though.

Hard to figure what it would be as a mistake in placement of rigging or spreaders would cause looseness one place but wire that wouldn't fit in another.

Some questions come to mind:

-Is it possible the turn buckle on the bob stay was loosened and needs to be brought back in? Is your bow sprit riding up? Is the turnbuckle under the roller furler (if you have one) back to is normal position?

-Any chance the main spreaders were made to mizzen length, or got swapped?

-Any chance you swapped two of the main lowers for the split backstays? The lowers are two feet longer than the splits.

-Did you run the back stay to the chainplates furtherst aft?

-Maybe the mast shrunk when you pulled the paint off?

Interested to know what you figure out.

RR

[ Edit | View ]

[> [> tuning -- Craig M31-25 Hibou, - Wednesday - 07/ 8/09 - 10:13am

Let it all out and tighten each wire the same number of turns until the whole rig is lightly tensioned.
I had the same issue with Hibou; the backstay turnbuckles were tightened all the way but the backsatys were slack. It turned out the whole rig was over tightened and was crushing the cabin top which made the closet and cabin doors hard to open and close.

[ Edit | View ]

[> [> [> could be my problem too? -- David Barrow, - Tuesday - 07/21/09 - 10:40pm

after reading your post, I recall my cabin doors are sticking and the engine hatches are too tight, perhaps I've overtightened my rigging so that I'm crushing the cabin and deck.

[ Edit | View ]

[> Check the bobstay -- Capt'n Mike, - Wednesday - 07/ 8/09 - 10:56am

I had this problem when the bobstay was too loose. The bowsprit on my TM-36 Ketch floats, so if it is too loose, you will not have enough space on the backstay turnbuckles. I would check this first.

[ Edit | View ]

[> [> More tuning the rigging -- Lyle harris, - Wednesday - 07/ 8/09 - 11:49pm

Thanks for all the observations here! A good friend of mine is an experienced wooden boat guy who went over all possible clues.
chain plates are solid. no movement there.
Forestay turnbuckle was not evenly threaded, so couldn't tighten all the way down.
Bobstay was tight enough, no rise in the bowsprit.
One turnbuckle on the backstay had a toggle, the other didn't. I removed the toggle to gain another 2 inches there.

We loosened everything up, and worked on the mid-mast shrouds that connect at the spreaders. Once we had that looking right, we worked on the upper shrouds, forestay and backstay. Unfortunately, I'd forgotten the SS wire for seizing the spreaders to the rigging, so the sagging issue will be addressed tomorrow.
the end result is that i can get the tension/tautness I need in the backstay and shrouds now. Once I get the spreaders set, I'll have to give the boat some sea trials and see what the rigging wants to do.
cheers,
Lyle
ps: M31 #42 will be named Grey Wolf. We'd played with the name starlight since we bought her in October, but it didn't seem a good fit, and there is another "starlight" in the harbor.

[ Edit | View ]

[> M 31 tuning the rig -- Al LaChance and Hexli, - Sunday - 07/19/09 - 10:50pm

Alright, along the same line of conversation, it would appear that my mail has a bit of "bend". I am trying to make the rig correct and currently the roller furling halyard is laying on the spreader "brackets" and I am seriously afraid of chafe.
I had the boat Pro rigged and I am sot so sure it is "right". is there a way to take the bend out, at least some of it? It would appear that my mast is pre-bent in that when it was down the bend did not come out. I have already replaced the deck and the step that supports the main mast and all appears to be sound.
Do we or should we come up with a way to tune our rigs and print it. I am not the one to do that, I bow to the knowing ones among us.
Speak to me and set me right!

Al

[ Edit | View ]

[> [> mast curvature -- Lyle Harris, - Tuesday - 07/21/09 - 11:42am

Hi Al,
Which direction is the curve/bend in your mast?
I'm trying to picture how the roller furling halyard comes into contact with the spreader brackets. I still have old hank-on foresails. Does this halyard pass through the "triangle" between the mast/spreader/top-shroud?
If you're referring to the curvature of the mast toward the stern of the boat, this is built into the design, and should be a subtle amount of curve on on side of the mast. More of a taper, actually.

[ Edit | View ]

[> [> [> It bends aft...mine too -- Randall, Murre, M31, - Tuesday - 07/21/09 - 2:03pm

If you'll look through owner photos on the MOA site, you'll notice that the bend in the main is fairly common, though I can't tell why. The original drawings suggest it wasn't designed that way.

All the fore and aft ***taper*** in the mast is on the fore side, so maybe this creates an ocular effect that encourages us to work in a bend over the years. Or maybe it was a fashion statement by a cadre of J-boat enthralled riggers. I've always thought the aft bend on Murre was due to a head sail roller rig that was cut too big. Who knows?

You can work most of the bend out, assuming you have enough of a run on your fore and backstay turnbuckles. But even with most of it out of Murre's main, the taper in the mast means the jib halyard still rests on the fore end of the spreader hardware. I have a rope to wire halyard on the jib that is bar taught; it's the wire that rests against the spreader tang, and it doesn't move, so I've not worried much about it.

If you've got all rope, you might stitch a bit of leather onto the chafing part of the halyard.

Good Luck,

RR

[ Edit | View ]

[> Rig tuning -- Doug Wilson, - Tuesday - 07/21/09 - 4:03pm

I'll be pulling both masts next month. The main has a bend aft, the rigger in La Paz said that was the design.
I wanted to pull both masts in May, due to woodpeckers in San Carlos, but the rigger there said that it would be better to leave them standing, rather than laid out horizontal for 4 months.
Funny how the folks who warned me of woodpeckers had aluminum spars, after talking with folks with wood spars said they had no problems over 10-11 years of storage there.
Will be interesting to see when I go back next month.

[ Edit | View ]

[> [> I have a theory about the mast bend -- Jared Kibele, - Thursday - 07/23/09 - 1:04pm

My main mast was very bowed when I got my boat (M31 #9 - I still need to submit info for the owner's page). I've been thinking about it a lot and trying to figure out if it's supposed to be that way for a long time. I decided it's not. I think it's supposed to be straight and raked aft by around 2 degrees like my mizzen is. I decided that based largely on this drawing: http://www.marineryachts.com/m31/sketch.JPG

On this drawing, the masts are completely straight and look like their raked back a couple of degrees. I also noticed that, in the drawing, the main shroud chain plates are in straight line with the spreader tangs and the masthead. In contrast to that, look at this photo of my masts: http://www.flickr.com/photos/kibele/2853986191/sizes/o/in/set-72157608843543865/ ...I've gotten the main a little straighter since then but it's still not perfect.

For a long time, I couldn't figure out how I could get the mast straight and I thought the problem was with the length of the fore and aft stays but now I think I've figured it out. I think the base of my main mast is the real problem. I think the base of my mast is vertical or possibly even raked forward a bit. If you look at the line drawing and imagine changing the angle of the base of the main mast while keeping the rest of the rigging as it is (so the masthead would still be in the same place), you can see that it would put the spreader tangs forward of where they are in the drawing and force the spreaders to angle back like they do on my boat.

So, to fix all this, I've got a plan. First, I'm reinforcing my saggy mast step (http://www.flickr.com/photos/kibele/sets/72157617972117480/) then I'm going to take down the main to replace my spreader tangs (there's a small crack in one). While the mast is down, I'm going to figure out some way to adjust the fore/aft angle of my mast step so that, rather than being vertical (or possible forward) as it is now, it will be angled back by about 2 degrees.

...and hopefully it'll all work out because it's a HUGE pain in the butt.

-Jared

[ Edit | View ]

[> [> [> With you on that... -- Randall, Murre, M31, - Friday - 07/24/09 - 1:38am

Jared,

The situation of the main on Murre looks similar to yours, and though I've worked much of the "bend" out, the spreaders still have a significant aft sweep like those on your boat.

I too have decided that this is due to a small forward rake of the mast ***below*** the spreaders, but I'm less certain about the need to adjust the angle of the step. It is logical that the acquiescing of the coach roof could cause the mast to fall forward as the step droops, but that much? I measured the angle of rake in the drawing you reference and it's about 3 degrees. But that's a tiny adjustment at the step.

Just thinking out loud.

I've passively attempted to pull the middle and lower part of the mast aft by adjusting the lowers, but that didn't really work. I think to realign with a straight aft rake will require taking all stays loose and starting the tuning process from the beginning, which I have not yet done.

Good argument though. I think you�ve got the problem right.

RR

Quickpost this image to Myspace, Digg, Facebook, and others!

[ Edit | View ]

[> [> [> [> I'm glad someone agrees -- Jared Kibele, - Friday - 07/24/09 - 1:30pm

I've talked to a number of people about this including a couple of boatwrights and riggers. Most of the time I've just gotten blank stares in response. ...I think this may be the first time I've been able to explain myself properly. Still, it's good to have someone who knows these boats so well agree with me.

I recently got a chance to see the inside of a slightly later Mariner 31 (hull #30-something just moved into my marina, John who's last name I can't remember - I have his card somewhere). I noticed that his mast step arch has two beams across where my boat (hull #9) only has one: (http://www.flickr.com/photos/kibele/3520930768/in/set-72157617972117480/). So I think my boat is particularly susceptible to having the roof cave in under the main mast and, with only one narrow beam, fore or aft tilting seems especially likely.

To complicate matters more, the whole deck and house including the coach roof were rebuilt by a previous owner so it's entirely possible that he angled the mast step incorrectly.

With my temporary compression post thingy, I've already raised the roof by about a half inch and I'm building steel braces for both sides of the mast support arch. I'm going to take the mast down soon and when I do, I think I'm going to brace the roof behind the mast support arch. Once that's done, I want get a bronze wedge made to put under the mast step to get the rake back into the bottom of the mast.

Should be a piece of cake, right?

-Jared

[ Edit | View ]

[> mast bend -- Dan M32 #36 Independence, - Thursday - 07/23/09 - 12:52am

How much mast bend are we talking about here? My main mast was lying unsupported over the cabin top for nearly 20 years and seems to have maybe an inch deflection in it. It's hard to tell how much while it's horrizontal as it bends with it's own weight.
Dan

[ Edit | View ]

[ Contact Forum Admin ]

Forum timezone: GMT-5
VF Version: 3.00b, ConfDB:
Before posting please read our privacy policy.
VoyForums^(tm) is a Free Service from Voyager Info-Systems.
Copyright © 1998-2019 Voyager Info-Systems. All Rights Reserved.