floater

tuning a single spreader, fractional rig.

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admittedly not the best picture - but between the deck and the forestay attachment this rig appears ever so slightly inverted. This can be cured by adjusting the backstay (it is rigged with a decent block and tackle) - but still. If you let go the backstay, it doesn't seem right that the rig inverts.

this boat is new to me, and none of the rigging feels super tight. it seems to me that if I tighten the uppers - perhaps problem solved - but how should this relatively simple rig be properly tuned? the po did leave me with a rigging tension gauge - apparently he was goofing around with it..

Note that the spreaders are swept back. The uppers terminate near the forestay attachment, and the lowers right beneath the spreaders.

 

514855775_singlespreaderfractionalrig.thumb.jpg.d4e965f32879459d9e95d3e3c8e0821c.jpg

 

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Set it up with the tension gauge according to the instructions and see where you end up first.

If rigging feels a bit loose it's actually a lot loose. The old rule of thumb for wire was 15% of breaking strength - that's really tight.

Is the gauge a Loos? I've used them a time or two and they work pretty well - way better than doing it by eyeball and/or feel.

As an illustration, I once bought a cutter that had 13 stays in total. The rig looked good and the stays felt fairly equally tensioned but when I checked them with the Loos I found they varied from less that 5% to over 24%

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If you really think the mast is inverted, tighten the shrouds. 
 

lowers will pull the mid section back. Uppers will help tighten the headstay

you might also be able to tighten the headstay if needed. 

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4 hours ago, mgs said:

If you really think the mast is inverted, tighten the shrouds. 
 

lowers will pull the mid section back. Uppers will help tighten the headstay

you might also be able to tighten the headstay if needed. 

its almost like I want to ease off on the forestay - oddly enough, the inverted section (it is quite slight) is right where the spreaders are..

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5 hours ago, SloopJonB said:

Set it up with the tension gauge according to the instructions and see where you end up first.

If rigging feels a bit loose it's actually a lot loose. The old rule of thumb for wire was 15% of breaking strength - that's really tight.

Is the gauge a Loos? I've used them a time or two and they work pretty well - way better than doing it by eyeball and/or feel.

As an illustration, I once bought a cutter that had 13 stays in total. The rig looked good and the stays felt fairly equally tensioned but when I checked them with the Loos I found they varied from less that 5% to over 24%

um. instructions?

fuck. did I not ask the po for those? shit me. ;)

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Look on the Interweb.

Loos gauges have them right on them - just select the size of wire you are checking to see how much deflection is correct

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50 minutes ago, SloopJonB said:

Look on the Interweb.

Loos gauges have them right on them - just select the size of wire you are checking to see how much deflection is correct

so. tuning the rig is just about tension - is this possible? Somehow I assumed that geometry also played a role - as in length of stays..

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A wire that is tensioned to 15% of B/S is at 15% whether it's 20' long or 40' long.

A longer wire will stretch more distance to get to that same 15% because stretch is a percentage of length.

So the longer wires will take more turns on the screw to reach that tension.

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Rigs are tuned from top to bottom.

1. Connect the wires and set mast rake with the forestay. Hand-tighten the shrouds and make sure the mast is centered/vertical.

2. Tension the backstay to induce some bend and start tightening the uppers symmetrically by counting turns on the turnbuckles. Release the backstay if you want to check tension with the Loos and re-tighten before working in the turnbuckles. The mast should have significant prebend after this step, because you are going to remove bend in the next step.

3. Release the backstay and tighten the lowers symmetrically (same number of turns on each side). Make sure the mast stays straight athwartships. Correct sideways bend if necessary by releasing one and tensioning the opposite side. Continue tensioning for desired prebend. If the mast inverts at the spreaders there is too much tension in the lowers relative to the upper shrouds.

(4.) On your rig the shrouds control headstay tension since there is a long and bendy piece of mast between the headstay and the masthead. If you want more headstay tension you need to tighten your shrouds. Limiting the bend with the lowers is important to keep the mast from bending under compression from the headstay which will decrease your headstay tension.

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11 hours ago, floater said:

its almost like I want to ease off on the forestay - oddly enough, the inverted section (it is quite slight) is right where the spreaders are..

Slack the headstay off then.  If you think it’s forward at the spreaders tighten the lowers up. 

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Wow!!! We rig boats virtually every day and as I read all the posts above I didn’t see ANYTHING like I would write. So here goes...

Quick response.

If that rig is inverted, I suspect the lowers are too tight (.... with respect to EVERY other factor)

-//

How to tune that rig?

1. Loosen EVERYTHING until the mast is standing as a straight pole. (If the mast remains bent with everything sloppy, the extrusion is bent . For these directions, I will assume it is not bent ) 

2. As I have ZERO idea how much rake this particular boat needs to balance the helm, I would start out with the assumption it ought to set up like most other similar boats. I would would hand tighten their uppers and forestay so the mast  is centered side to side and leans back a little(I am going into this knowing I will have to take the boat for a ride to see how it sails but I would lean the mast back so the top is 15 to 30cm back from the base ( six inches to a foot for USA sailors) 

For centering I would cleat the main halyard so I would have to push down the shackle with about a couple kilos of force to touch the top of the gunwale. 
Then I would  try touching the shackle to the same spot on the other side if the boat. I might try touching two or three pairs of symmetrical spots on the boat until i would convince myself the tensions are about equal. 
(This is accomplished to perfection is you and a friend Each check and AFTER you have checked tell the other what you think. When you agree it is the same on both sides, it is) 

3. I would tighten the Uppers to about 200  kilos or 400 lbs or until there is about 3 to 9cm (2 or 3 inches)  of pre-bend. I would check by holding the bottom of  the main halyard  against the mast. The gap at the spreaders is the amount of pre-bend. (That  tension should be safe for eventual testing in about ten knots of breeze) 

4. I would tighten the lowers to bring the pre-bend back to about 2/3 of where it was with totally sloppy lowers. This might be about 150 kilos (300 lbs) but the function is the key NOT the tension number. 
The function of the lowers is to keep the middle of the mast from going further forward. When you load the forestay, the pre-bent mast will want to continue to bend. That bending would make the distance from the deck to the forestay attachment point shorter and the forestay would never get tight.

**The lowers control the tension of the the forestay 

5. The backstay ... it really has no function on this to until it is used to depower the rig. Pulling on the  backstay bends the mast ABOVE the forestay attachment point. (Yes, it does tighten the forestay a bit and it bends the mast a bit more forward at the spreaders...  and I could go on all day about the various subtleties including varying the rig tune for various wind conditions) 

Anyway, the backstay flattens the top section of the sail and opens the leech at the top of the sail and gets rid of the healing force when there is too much wind to effectively use the  full power of your sails. 
 

what do you do?? You see a puff coming and you grab the backstay line. As the puff hits you tighten the backstay to keep the boat upright. The rest of your sailplane stays trimmed for ultimate upwind sailing and you charge forward blasting past those fools who eased the traveler, closed the slot,  and quit pointing. 
 

The testing: Go for a ride. 
* If the leeward shrouds becomes horribly sloppy, tighten the rig. Rule of thumb ?? Tighten the uppers two full turns and tighten the lowers one and a half turns and try it again.

*If the boat has Lee helm, go back to step two. Your rig is already centered but you are going to lean the mast back some more and try again 

*If the boat has too much weather helm, AND YOU ARE KEEPING IT FLAT ENOUGH, you may wish to stand the mast up more vertically. 
 

Tension settings: A fractional rig set up to properly perform in 25 knots will be absurdly over tight for winds under 12 and will sail horribly.

A fractional rig set up loosely  enough for ultimate performance in five knots will be horribly overpowered and may even fold up and fall in big breeze. 
 

We generally set up our customers’ boats for 12 to 15 and give them instructions about how to mess with the rig to make it work better in other conditions. 
 

Whoever makes sails for your boat will usually be happy to give you a chart of rig tensions for various conditions. They want you to have great performance with their stuff and proper rig tension helps a lot. 
 

—- Left out... while sailing upwind, stand by the front of the mast and look up. The mast should not bend sideways. You may have to adjust the relative tensions between the uppers and lowers to straighten the mast.

If the mast bends to weather at the spreaders, tighten the uppers a bit and loosen the lowers a bit. 
It the mast sags to leeward at the spreaders, tighten the lowers a bit and ease the uppers a bit 

And.... check EVERYTHING on both tacks 

 

phooey... I was going for a sail an hour ago ... outta here !!! 

 

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Gouv, I don't see anything in that where you use any kind of tension measuring tool on the wires.

Is that the case - are you saying thumb and eye is all you use?

If that's the case do you also tighten keel bolts with a wrench and a piece of pipe "until the suckers scream" or do you use a torque wrench?

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1 hour ago, SloopJonB said:

Gouv, I don't see anything in that where you use any kind of tension measuring tool on the wires.

 

Read 3 and 4 again, and the rest of the post for that matter.

Its all about setting the rig up to perform and bend like it should, different wind strengths = different tensions.

If you want to go ahead and tension your rig to xxx because the wire is yyy thick, good luck getting your mast to do anything useful. If you up your wire size what you going to do then? Bit like torquing your keel up as the hull material is crushing because you reckon the bolts can handle a higher torque.

Fractional rig a bit more technical than a power-pole, its shape and change in shape that matter.

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3 hours ago, Gouvernail said:

Wow!!! We rig boats virtually every day and as I read all the posts above I didn’t see ANYTHING like I would write. So here goes...

Quick response.

If that rig is inverted, I suspect the lowers are too tight (.... with respect to EVERY other factor)

-//

How to tune that rig?

1. Loosen EVERYTHING until the mast is standing as a straight pole. (If the mast remains bent with everything sloppy, the extrusion is bent . For these directions, I will assume it is not bent ) 

2. As I have ZERO idea how much rake this particular boat needs to balance the helm, I would start out with the assumption it ought to set up like most other similar boats. I would would hand tighten their uppers and forestay so the mast  is centered side to side and leans back a little(I am going into this knowing I will have to take the boat for a ride to see how it sails but I would lean the mast back so the top is 15 to 30cm back from the base ( six inches to a foot for USA sailors) 

For centering I would cleat the main halyard so I would have to push down the shackle with about a couple kilos of force to touch the top of the gunwale. 
Then I would  try touching the shackle to the same spot on the other side if the boat. I might try touching two or three pairs of symmetrical spots on the boat until i would convince myself the tensions are about equal. 
(This is accomplished to perfection is you and a friend Each check and AFTER you have checked tell the other what you think. When you agree it is the same on both sides, it is) 

3. I would tighten the Uppers to about 200  kilos or 400 lbs or until there is about 3 to 9cm (2 or 3 inches)  of pre-bend. I would check by holding the bottom of  the main halyard  against the mast. The gap at the spreaders is the amount of pre-bend. (That  tension should be safe for eventual testing in about ten knots of breeze) 

4. I would tighten the lowers to bring the pre-bend back to about 2/3 of where it was with totally sloppy lowers. This might be about 150 kilos (300 lbs) but the function is the key NOT the tension number. 
The function of the lowers is to keep the middle of the mast from going further forward. When you load the forestay, the pre-bent mast will want to continue to bend. That bending would make the distance from the deck to the forestay attachment point shorter and the forestay would never get tight.

**The lowers control the tension of the the forestay 

5. The backstay ... it really has no function on this to until it is used to depower the rig. Pulling on the  backstay bends the mast ABOVE the forestay attachment point. (Yes, it does tighten the forestay a bit and it bends the mast a bit more forward at the spreaders...  and I could go on all day about the various subtleties including varying the rig tune for various wind conditions) 

Anyway, the backstay flattens the top section of the sail and opens the leech at the top of the sail and gets rid of the healing force when there is too much wind to effectively use the  full power of your sails. 
 

what do you do?? You see a puff coming and you grab the backstay line. As the puff hits you tighten the backstay to keep the boat upright. The rest of your sailplane stays trimmed for ultimate upwind sailing and you charge forward blasting past those fools who eased the traveler, closed the slot,  and quit pointing. 
 

The testing: Go for a ride. 
* If the leeward shrouds becomes horribly sloppy, tighten the rig. Rule of thumb ?? Tighten the uppers two full turns and tighten the lowers one and a half turns and try it again.

*If the boat has Lee helm, go back to step two. Your rig is already centered but you are going to lean the mast back some more and try again 

*If the boat has too much weather helm, AND YOU ARE KEEPING IT FLAT ENOUGH, you may wish to stand the mast up more vertically. 
 

Tension settings: A fractional rig set up to properly perform in 25 knots will be absurdly over tight for winds under 12 and will sail horribly.

A fractional rig set up loosely  enough for ultimate performance in five knots will be horribly overpowered and may even fold up and fall in big breeze. 
 

We generally set up our customers’ boats for 12 to 15 and give them instructions about how to mess with the rig to make it work better in other conditions. 
 

Whoever makes sails for your boat will usually be happy to give you a chart of rig tensions for various conditions. They want you to have great performance with their stuff and proper rig tension helps a lot. 
 

—- Left out... while sailing upwind, stand by the front of the mast and look up. The mast should not bend sideways. You may have to adjust the relative tensions between the uppers and lowers to straighten the mast.

If the mast bends to weather at the spreaders, tighten the uppers a bit and loosen the lowers a bit. 
It the mast sags to leeward at the spreaders, tighten the lowers a bit and ease the uppers a bit 

And.... check EVERYTHING on both tacks 

 

phooey... I was going for a sail an hour ago ... outta here !!! 

 

I’ll agree with this.
 

It seems from my comments that I thought the mast was inverted the other way. Must be a post solstice mind trick

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2 hours ago, SloopJonB said:

Gouv, I don't see anything in that where you use any kind of tension measuring tool on the wires.

Is that the case - are you saying thumb and eye is all you use?

If that's the case do you also tighten keel bolts with a wrench and a piece of pipe "until the suckers scream" or do you use a torque wrench?

To be honest?? Most Of the boats I handle can be competently rigged using “it feels about right.” I have a variety of gauges including a nifty antique one I like to bust out simply to see the looks on the faces of those observing me. 
 

For  a fractional rig like those on J-24 and J-29 the mast base position adds another layer I did not address above. For some reason I “just assumed” that boat’s  mast is deck stepped. I can’t really see in the photo. 
 

I have no idea how to measure the 200 kilo starting tension guess without a gauge. 
 

If it is a fractional rig, and I have the opportunity to sail the boat for a few hours in a variety of wind velocities, the guage serves a valuable bunch of purposes. 
**I can check to be certain I am not overtightening the rig. It is easy to crank on more tension than the rig and boat structure should be asked to handle. 
( note: on my J-22 and J-24 I have ALWAYS eased off some tension after a windy race day. Nothing good comes from storing a boat with a tight rig) 

** I can record the set up tensions so I can rapidly repeat a known previously successful  set up when the winds look similar 

**I can communicate with other sailors who can tell me why my speed was fine but my pointing was pathetic.. 

**I can write down how many turns I added or subtracted from one setting to another  and how that changed the tension. 

>>>Mostly, I set up the rig  so the mast bends the way I want it to bend so the available sails are most likely to drive the boat. The sailmaker usually provides a chart but the slightest change in luff curve or the relationship of wind velocity to wave height will change the very best tuning guide into nothing more than a general reference. 
 

€€€€€ Torquing keel  bolts. Whenever  I see torque numbers I wonder whether the torque numbers apply to well lubricated threads,  dry threads, a greased washer, boat sitting on keel, keel hanging, and whether somebody has done any real calculations.

The correct amount of torque is enough to keep the keel absolutely firm against the sump and is limited not just by the strength and stretching SS if the bolt but by the pressure necessary to deflect the sump bottom. 
 

translation: I have a few torque wrenches and when someone gives me credible information about torque settings, I use the tools and hope to thereby protect my savings from greedy lawyers and their clients. 

 


 

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39 minutes ago, mgs said:

I’ll agree with this.
 

It seems from my comments that I thought the mast was inverted the other way. Must be a post solstice mind trick

THE DAYS ARE GETTING LONGER!!!! 
and... it was a great Christmas afternoon for an AERO ride. I had to share the lake with a half dozen Opti sailors, two inflatables carrying coaches, a couple coaches on kayaks, two passing runabouts, a pair of J-80s, a Columbia 9.6, a Hunter 31, a Catalina 22, an Ensign, and about three other boats I failed to identify and remember. 

     
 

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5 hours ago, BOI Guy said:

Read 3 and 4 again, and the rest of the post for that matter.

Its all about setting the rig up to perform and bend like it should, different wind strengths = different tensions.

If you want to go ahead and tension your rig to xxx because the wire is yyy thick, good luck getting your mast to do anything useful. If you up your wire size what you going to do then? Bit like torquing your keel up as the hull material is crushing because you reckon the bolts can handle a higher torque.

Fractional rig a bit more technical than a power-pole, its shape and change in shape that matter.

I was thinking more along the line of port and starboard lowers having the same tension, both uppers equal - like that.

I've had masts that were straight and stayed that way on both tacks but there were big differences in the tension on opposing wires.

That can't be good.

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21 hours ago, Gouvernail said:

Tension settings: A fractional rig set up to properly perform in 25 knots will be absurdly over tight for winds under 12 and will sail horribly.

21 hours ago, Gouvernail said:

Whoever makes sails for your boat will usually be happy to give you a chart of rig tensions for various conditions. They want you to have great performance with their stuff and proper rig tension helps a lot. 

A fractional rig set up loosely  enough for ultimate performance in five knots will be horribly overpowered and may even fold up and fall in big breeze. 

endless thanks for your post. bravo. I'll report back how it goes.

also, the sails pretty much never used Pineapples - but somehow (even) they screwed up on the foresail shape. I'm going to have to twing the clew down as the jib track too far aft. The main a fully battened (and crispy) Pineapple as well - can't wait to see it.. :) 

and I don't require ultimate performance. This is a cruising boat on SF bay (for the children - wink) so definitely sees variable conditions. big breeze prominently among them.

18 hours ago, BOI Guy said:

Fractional rig a bit more technical than a power-pole, its shape and change in shape that matter.

Power pole you say? My previous boat a Cal. So yeah, this bendy spar definitely something new. Which brings me to a related question.

Can the masthead support my weight (< 200 lb.) aloft? I have jumar'ed my way up to the forestay attachment. But the skinniness of this rig above that makes me wonder if its safe to climb all the way to the top?

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13 minutes ago, floater said:

endless thanks for your post. bravo. I'll report back how it goes.

also, the sails pretty much never used Pineapples - but somehow (even) they screwed up on the foresail shape. I'm going to have to twing the clew down as the jib track too far aft. The main a fully battened (and crispy) Pineapple as well - can't wait to see it.. :) 

and I don't require ultimate performance. This is a cruising boat on SF bay (for the children - wink) so definitely sees variable conditions. big breeze prominently among them.

Power pole you say? My previous boat a Cal. So yeah, this bendy spar definitely something new. Which brings me to a related question.

Can the masthead support my weight (< 200 lb.) aloft? I have jumar'ed my way up to the forestay attachment. But the skinniness of this rig above that makes me wonder if its safe to climb all the way to the top?

Can you put a strop on the bottom of the jib to change the lead back far enough? That's what I had to do with my Shark jib.

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On 12/25/2019 at 5:55 AM, mgs said:

Slack the headstay off then.  If you think it’s forward at the spreaders tighten the lowers up. 

aft at the spreaders but just a tiny bit. tbh. the po may have been following the correct steps - as all stays feel evenly tensioned and the spar virtually straight. but, he had only gotten to Gouv's step #2, and yes - perhaps had the forestay a bit too tight. He also messed up here a bit here his installation of the furler.. another but perhaps related story.

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3 minutes ago, Ishmael said:

Can you put a strop on the bottom of the jib to change the lead back far enough? That's what I had to do with my Shark jib.

I had great hopes for this, as I corrected the furler installation by raising the head. Alas, a six inch pennant did not bring the clew up far enough.

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16 hours ago, SloopJonB said:

I was thinking more along the line of port and starboard lowers having the same tension, both uppers equal - like that.

I've had masts that were straight and stayed that way on both tacks but there were big differences in the tension on opposing wires.

That can't be good.

Last summer I stepped onto a friend’s boat for a beer an race and the Genoa set up WAY WAY different on the two tacks.  I had him center the traveler and tack and the leech was about 4” more curvy (the best word I have for its sag to leeward) on one tack. 
At the dock after  the race I felt the shrouds... they felt about the same.

We got out the gauge and the uppers (mast head rig) were about equal. The lowers were significantly tighter on the same side as the slightly tighter upper. 

Two of us did the main halyard to the deck touching routine and the rope seemed to be over an inch longer when stretched on one side. As neither of us could figure out how the line would grow and shrink we decided the mast wasn’t centered. ( note... the tight side wires were on the side where there was a longer distance from the mast head to the deck. ) 

The boat is a Pearson 26. They have a horribly under constructed mast support and I NEVER put much tension on Pearson 26 rigs. 

so... we sloppied the lowers, centered the mast with the uppers, tightened the uppers hand tight, and then firmed up the lowers to hand tight. 
(My version of hand tight is:  While holding the wire  twisting the turnbuckle as hard as I can with my fingers. Pearsons generally have the obsolete backasswards Navtek fitting with the nut in the middle of a right and left hand stud., The parts on the wire and deck fitting are threaded on the inside. 
I generally use tools to tighten a couple more turns beyond hand tight but the Pearson mast step really does not need any extra stress....

and while I am digressing,,, I have rebuilt most of cross beams under the mast steps On about thirty Pearson 26 and none of my my new beams dating back to 1982 has needed more repair but ...

The oak poles that support the cross beam sit on 3/8” bolts that pass through through rather thin fiberglass and I have seen those fiberglass holes wallow out a bit and / or the interior sections of the cabin sag.

The boat simply is not constructed to withstand lots of mast compression.

 

anyway.... I agree with @SloopJonB gauges provide  all sorts of helpful information. 
 

I also love to put lots of telltales on my sails and cassette tapes on my shrouds   And those mast head flys and windy doodles on Lasers and the AERO are handy tools that often clue me in on winds I haven’t yet felt. 

 

Done with lunch... 
 

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um, just how do you adjust  mast rake on a fractional rig?  lengthen the forestay, shorten the backstay?     there's also a roller furler up there, so not so sure how the forestay will be shortened ...      just for my clarity, what do you mean inverted?   bowing forward or aftward?

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On 12/26/2019 at 8:25 AM, SloopJonB said:

 

If that's the case do you also tighten keel bolts with a wrench and a piece of pipe "until the suckers scream" or do you use a torque wrench?

He broke his first torque wrench with the piece of pipe so he went back to the big wrench. 

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9 hours ago, Grande Mastere Dreade said:

um, just how do you adjust  mast rake on a fractional rig?  lengthen the forestay, shorten the backstay?     there's also a roller furler up there, so not so sure how the forestay will be shortened ...      just for my clarity, what do you mean inverted?   bowing forward or aftward?

On a fractional rig the forestay length sets the mast rake, same for a masthead rig. Some furlers have the ability to be adjusted for length, some do not.

Inverted means the middle of the mast bows aft. Prebend is the middle of the mast bowing forward. 

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10 hours ago, Grande Mastere Dreade said:

um, just how do you adjust  mast rake on a fractional rig?  lengthen the forestay, shorten the backstay?     there's also a roller furler up there, so not so sure how the forestay will be shortened ...      just for my clarity, what do you mean inverted?   bowing forward or aftward?

Forestay length. The backstay is nearly always adjustable on a tackle so you can tune it when sailing. 

If your furler doesn't have adjustable forestay length then you can make it longer by adding another toggle at the deck level, making it shorter is a bit more tricky as you have to cut down the forestay. 

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Suspicion:

The new roller furler is Set up too short . The lowers were not eased when the mast was pulled forward to hook up that roller furler.

either you can adjust something to Lengthen  the forestay oR you can’t ( or it is already maxed out. IF THERE ARE HOLES IN THE TURNBUCKLE SCREWS FOR COTTER PINS DO NOT EASE THE TURNBUCKLE SO FAR YOU CANNOT ACCESS THOSE  LITTLE HOLES.  You don’t want the turnbuckle to unscrew and come apart. 
some roller furlers are the forestay other roller furlers have the forestay running though their tube.

Most furlers that serve as the forestay can be adjusted. 
most forestay shave a turnbuckle for making adjustments 

 

**** if you find the boat has Lee helm and there is no more available Method for lengthening the forestay / roller furler .,,. You can add rigging toggles or buy a new forestay.  an entire new forestay won’t cost $300 but don’t buy one until you are certain what itbis you want.

there are great rigging professionals in most sailing communities. At some point, calling the pro is a very good idea. 
**”  I am Going to use this when you aren’t around. Please treat me like this is my first boat and try to set me up so I can understand not just how but why. “

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16 hours ago, Gouvernail said:

Suspicion:

The new roller furler is Set up too short . The lowers were not eased when the mast was pulled forward to hook up that roller furler.

either you can adjust something to Lengthen  the forestay oR you can’t ( or it is already maxed out. IF THERE ARE HOLES IN THE TURNBUCKLE SCREWS FOR COTTER PINS ..

Whoa!. when you're good, you're good. But g*ddamn if that isn't the only piece of information the PO gave me on this boat: "you'll need to add a cotter pin to the head stay". Which is kind of ironic because ton's of undisclosed shit wrong with this "gift horse" but I guess he figured that was a safety issue..

Its a Harken - something new to me - and I eyeballed it just yesterday and wasn't sure how it assembled. But just watched a vid. and perhaps now I can proceed. 

Also, your notion of 'lowers too tight' may be spot on as well. I'll try to break out that tension gauge today for more info, and perhaps snap a pic or two. 

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Harken furlers have a dab of red paint on the turnbuckle screw to mark where you should not unscrew further.

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On 12/27/2019 at 9:54 AM, ctutmark said:

On a fractional rig the forestay length sets the mast rake, same for a masthead rig. Some furlers have the ability to be adjusted for length, some do not.

Inverted means the middle of the mast bows aft. Prebend is the middle of the mast bowing forward. 

yeah i know,  fractional rig for 10+ years,   you going to let out the turnbuckle maybe an 1" , you going to get that much mast rake? don't think so..    and the question about inversion is to make sure we're all on the same page...    

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If your furler doesn't have adjustable forestay length then you can make it longer by adding another toggle at the deck level, making it shorter is a bit more tricky as you have to cut down the forestay. 

and if your inners aren't tight enough and when you crank on that backstay all you are going to do is put more mid mast bend in...

personally,  i'd take the boom off, ease the backstay and side stays, and then take a look at the mast..  as guv says, if inverted the mast is farcked..  if it's fine, start the tuning with a tape up the mast and get it centered..  tighten them to your specs,   tighten the inners to specs but be sure your don't throw an S shape into the mast  ( lie on your back and sight up the mast from the cabin top) .. now set your fore stay length...   hopefully , you're good to go..

Quote

The new roller furler is Set up too short . The lowers were not eased when the mast was pulled forward to hook up that roller furler.

this makes the most sense..

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22 minutes ago, Grande Mastere Dreade said:

yeah i know,  fractional rig for 10+ years,   you going to let out the turnbuckle maybe an 1" , you going to get that much mast rake? don't think so..    and the question about inversion is to make sure we're all on the same page...    

and if your inners aren't tight enough and when you crank on that backstay all you are going to do is put more mid mast bend in...

 

personally,  i'd take the boom off, ease the backstay and side stays, and then take a look at the mast..  as guv says, if inverted the mast is farcked..  if it's fine, start the tuning with a tape up the mast and get it centered..  tighten them to your specs,   tighten the inners to specs but be sure your don't throw an S shape into the mast  ( lie on your back and sight up the mast from the cabin top) .. now set your fore stay length...   hopefully , you're good to go..

That's fine with inline spreaders, not so much on swept spreaders.

Pretty easy to work out how much a 1" headstay ease changes the rake if you know the mast length, forestay length and the J dimension. Or you can hang a weight off the main halyard and directly measure the change

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52 minutes ago, ctutmark said:

Pretty easy to work out how much a 1" headstay ease changes the rake if you know the mast length, forestay length and the J dimension. Or you can hang a weight off the main halyard and directly measure the change

Yes and no. In practice, not so easy. Headstay length changes alone usually change mast bend in a way not easily computed geometrically. Pure mast rake alone is more related to adjustments of lowers, partners and step with accomodating changes in the headstay. With a proportionally short J, a bendy mast and some rake a 1 inch headstay change could have a surprisingly big effect on the position of the masthead. Much more than the simple triangular estimate would predict. 

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10 hours ago, Grande Mastere Dreade said:

...

personally,  i'd take the boom off, ease the backstay and side stays, and then take a look at the mast..  as guv says, if inverted the mast is farcked..  

.. but then realized it was a keel stepped mast, so we moved the butt back a 1/4" and all is good again... life is mere perspectives into a myriad of problems, searching for a view.

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found this gem in the Selden manual: "The backstay must not be allowed to completely slacken at any time. If the masthead is able to move forwards, the mast is in danger of buckling aft. If using a tackle, put a stopper knot in the tail to limit the reduction in backstay tension. Right now, the backstay when fully released just flops around in the breeze. Okay, guess I can manage shortening the stopper knot..

Also, both the uppers and lowers are not much more than "hand tight" right now.

According to Selden, uppers should be tightened to 20% breaking strength. That would be 17 - right now at 6. 

upper.JPG.8276f12f19c4f81dd6336055db2cb1af.JPG

Lowers should be ?. Oddly enough, Selden gives no guidance here on tension for lowers. But simply mentions that the lowers should be used - in the initial tuning step - to straighten the mast. 10% of breaking strength would read 17. 15% 22. 

 

lower.JPG.45fab22bf5f536ca33f6b9e08adf7dc2.JPG

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21 hours ago, ctutmark said:

That's fine with inline spreaders, not so much on swept spreaders.

Pretty easy to work out how much a 1" headstay ease changes the rake if you know the mast length, forestay length and the J dimension. Or you can hang a weight off the main halyard and directly measure the change

more fun news concerning the swept back spreader (from Selden manual): "To ensure good fore-and-aft stability for this type of rig, it is very important that the leeward cap shroud is tight. This high level of pre-tension will generate deformation on all grp hulls. As far as strength is concerned, the hull should be able to support these loads, but the deformation will make it necessary to check the tuning while sailing. This is particularly important when the yacht is new and at the start of every season."

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update: I've taken apart the furler - lengthened the forestay a bit. Also, loosened then tightened uppers and lowers to get the mast vertical and the slight inversion is gone. A bit of intelligence now on the posts above:

On 12/24/2019 at 11:40 PM, Zonker said:

Selden has some good online generic rig tuning guides

unsexy but sound advice. rtfm. I did, and glad I did.

On 12/24/2019 at 1:11 PM, SloopJonB said:

Set it up with the tension gauge according to the instructions and see where you end up first.

The old rule of thumb for wire was 15% of breaking strength - that's really tight.

everyone likes a good rule of thumb, but (for my rig anyway) this is not good advice. DO NOT tension your shrouds according to diameter only! Also, Selden recommends taking the cap shrouds (uppers) up to 25%.

There are several responses above that make sense, but I got a PM from a Seattle based rigger, hat tip @ctutmark, that is both a rule of thumb and good advice!

  • "on a single spreader rig the lowers typically have 50% of the [absolute] tension of the uppers". Which means that although the lowers are of larger diameter, they end up tensioned to less load.
On 12/25/2019 at 12:37 AM, neuronz said:

Rigs are tuned from top to bottom.

1. Connect the wires and set mast rake with the forestay. Hand-tighten the shrouds and make sure the mast is centered/vertical.

2. Tension the backstay to induce some bend and start tightening the uppers symmetrically by counting turns on the turnbuckles. Release the backstay if you want to check tension with the Loos and re-tighten before working in the turnbuckles. The mast should have significant prebend after this step, because you are going to remove bend in the next step.

3. Release the backstay and tighten the lowers symmetrically (same number of turns on each side). Make sure the mast stays straight athwartships. Correct sideways bend if necessary by releasing one and tensioning the opposite side. Continue tensioning for desired prebend. If the mast inverts at the spreaders there is too much tension in the lowers relative to the upper shrouds.

(4.) On your rig the shrouds control headstay tension since there is a long and bendy piece of mast between the headstay and the masthead. If you want more headstay tension you need to tighten your shrouds. Limiting the bend with the lowers is important to keep the mast from bending under compression from the headstay which will decrease your headstay tension.

this post most closely mirrors the Selden manual - but explains it better. methinks neuronz be a rigger..

thank you everybody. Next up, a test sail - and I'll be keeping my eyes on that rig. (hopefully this weekend - I"ve owned this boat since before Thanksgiving and have yet to even sail it!).

 

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Just add one thing to some of the great advice given here......

Using the main halyard to centre the rig can be an issue if you have two sheaves at the masthead eg. main halyard and topping lift, as the sheaves are off centre.

Two ways around this are - 

Adjust the halyard as described above to that it touches a point on one side of the boat, then pull straight aft.  Pull the topping lift beside the main halyard and adjust so it is exactly the same length as the halyard, then use one for each side of the boat that their corresponding sheave at the masthead is.

Or.

If your mast is down/lowered, measure the see if your shrouds are the same length on both sides.  If they are then centre the rig using shroud length.  If they aren't then  make a mark using a sharpie the same distance from the top of each stay, close to the swage on the bottom, The centre the rig by measuring up from the chainplate to the mark.

 

If I am making new stays for a rig I always make both sides identical lengths which makes tuning so much easier.

 

Of course all this assumes that the chainplates are in the same place on the boat!!! If you want to get really fancy, the rig shoudl be centred to the keel, not the chainplates, so measure from each chain plate to the bottom leading edge of the keel!!!

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