Tyson0317

J/35 Rig tuning question

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I've shown this to a few people over the years (it's been the same since I got the boat in 2013) and it didn't seem to raise alarm with anyone, but never felt right to me.

Check out the video and tell me if you feel my shrouds are tight enough. Especially the inside, are super limp when heeled in this easy breeze. 

On my starboard side, I have a fair bit of adjustment that I could use to tighten them, but over on port, I have less than half an inch (maybe) of tightness left on the turnbuckle. 

 

 

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This is from a 2004 Doyle tuning guide for the J/109 that is posted on the J/109 class website tips & tuning page.  The settings are probably different for the J/35 but the concept of taking turns off for lighter breeze and putting turns on with more breeze could be used.

Quote

First with the 105% jib sail on each tack and check the tension of the leeward rigging. If it is loose tighten the leeward shroud one turn and then tack and tighten the new leeward side one turn until the leeward side is just beginning to unload in the puffs. This method is a good way to set the desirable tension for any given wind condition. It tightens the rigging on heavy days and eases it on light days. If the 155% [PHRF} genoa is utilized this same method should be used. This method has the desirable effect of giving you tighter rig tension when the larger headsail is used. For ideal tune, the D2's may need to be eased one or two turns when using the larger genoa is used and the D1's may want to be tightened one half or one full turn.

 

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Some boats have very slack leeward shrouds, Id check with the top J35 and see what they set them at.

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Something is wonky if you've only got a 1/2 inch left on the port turnbuckle (s) and a bunch more over on starboard. Either the rig is not really centered and in column, or the standing rigging is too long on one side or too short on the other.  Are the turnbuckle bodies and or the threaded sections the same length  between port and starboard?  Do the chainplates sit at different heights port and starboard?  Are your spreaders actually the same length?  

For that matter, how old is the standing rigging?  

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Go to www.j35.org  Under tips and tricks / tuning guides  there are three tuning guides located there from North, Russ Perry, and Shore Sails.  The Shore sails guide gives the most detail but useful information in all of them.  Then print out the form and join your class association as a thank you for keeping all this for you :-) 

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3 hours ago, Crash said:

Something is wonky if you've only got a 1/2 inch left on the port turnbuckle (s) and a bunch more over on starboard. Either the rig is not really centered and in column, or the standing rigging is too long on one side or too short on the other.  Are the turnbuckle bodies and or the threaded sections the same length  between port and starboard?  Do the chainplates sit at different heights port and starboard?  Are your spreaders actually the same length?  

For that matter, how old is the standing rigging?  

 

Or the turnbuckles were too tight on the studs before the shrouds were connected.

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Our lowers are usually somewhat loose and the uppers soft from the tight feeling when unloaded. See what the mast looks like, is it in column, hooked to leeward, hooked to windward? For the lowers you want to look at the main when you have backstay on, are you getting too much bend with it on?

With the thread length, check all the items noted above with a good tape measure and consistent measurement points.

After that then set the rig per your sail maker's tuning guide.

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When the yard re-steps our mast in the spring they are careful to engage each of the shrouds into its respective turnbuckle.  How far they engage the threads depends.  We find it convenient to go around afterwards to verify that the mast is plumb, is set for the rake we want, and (especially) that there are cotter pins fitted everywhere.    

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5 hours ago, PaulK said:

When the yard re-steps our mast in the spring they are careful to engage each of the shrouds into its respective turnbuckle.  How far they engage the threads depends.  We find it convenient to go around afterwards to verify that the mast is plumb, is set for the rake we want, and (especially) that there are cotter pins fitted everywhere.    

when I know my rigs set up pretty well and i need to have it pulled for some reason, I have in the past, put a few dabs of fingernail polish in the threads above and below the turnbuckles as a rough gouge of where to turn them back to..

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5 hours ago, Bump-n-Grind said:

when I know my rigs set up pretty well and i need to have it pulled for some reason, I have in the past, put a few dabs of fingernail polish in the threads above and below the turnbuckles as a rough gouge of where to turn them back to..

If you have the open style turnbuckles, best to get a micrometer and measure the distance between the turnbuckle screw ends once the rig is at base.  I made small labels using a label maker and stick them on ech turnbuckle with its base measurement (e.g. 1.89").  That way whenever I want to adjust the rig, I can always go back to base and check it.  On my turnbuckles each full turn is 0.1 inch length adjustment.  You don't know how many times I thought I went 3 turns and only did 2.5 or went CCW instead of CW.  I bought a digital micrometer on Amazon for less than $15 that works well.

Some tips for setting the rig.

1.  If you have a laser level available when the boat is on the hard, use it to check the mast in column with the tip of the keel.  This needs to be done after dark and is more visible if you wear red goggles.  If you don't have a laser level, you can use a step ladder about 3-6 boat lengths from the stern and tension a string.  Set the string so when you sight behind it to the boat the keel, transom centerline, gooseneck and mast tip are in column.

2.  An alternative is to use the water bucket trick to check the mast centered.  Fill a bucket with water and hang it from the main halyard.  Swing it over to one side just aft of the shroud with the bucket hanging lower than the deck line.  Mark the halyard with tape where it crosses the deck line.  Swing it to the opposite side.  If everything is square, the halyard mark should cross in the same place both sides.  Note that some boats are NOT square (e.g. the keel is not mounted exactly perpendicular with the deck).  If you do this after checking with the laser, record the position on port and stbd side so you can always recent the rig when it is pulled.  My previous J/30 was off by about 1" on the halyard marks.  My J/109 is exactly square.  Use the cap shrouds to center the top of the rig with the other shrouds loose

3.  Once the rig is centered, tension cap shrouds evenly to get a Loos gauge reading about half the desired final setting.  Start tensioning lower lower shrouds to take out slack to the same setting as the cap.

4.  Take a picture from the companionway looking up the mast so you capture the tip to as low on the mast as you can see.  The mast track should be visible.  Put the picture into a drawing program (I use PowerPoint) and draw a straight line from the lowest point in the center of the mast to the tip at the center.  Blow up the picture and see where the line and the center mast slot deviate.  You can compensate for misalignment by adjusting the appropriate turnbuckles as needed to reduce the misalignment.  You'll need to take multiple pictures after each adjustment to check the rig in column.

5.  Tension shrouds equally on both sides to move up toward your base rig tension.  Dont try and go all the way up at once since there will be interaction particularly with swept back spreaders.  Once you are at base settings on the Loos, do the mast in column check again and tweak turnbuckles as needed. 

6.  Measure the turnbuckle screws and record the measurements.  This will be a repeatable base setting you may always return to and it can be verified using the micrometer.

This doesn't say what the base settings should be but how to get to a setting that is repeatable.  Use a tuning guide or work with your sailmaker to find the best base setting.  When you find something you're happy with, record it! 

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Use your main halyard with some sort of strop and measure that the tip is centered.  Basically from the same fixed stanchion base on each side works.   I am assuming your mast butt is in a "normal Position" and straight.

After 23 years of centering the spar then dialing up the rig to the base setting it balances the stick to centered and the mast track is straight.

 

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29 minutes ago, proOC said:

Use your main halyard with some sort of strop and measure that the tip is centered.  Basically from the same fixed stanchion base on each side works.   I am assuming your mast butt is in a "normal Position" and straight.

After 23 years of centering the spar then dialing up the rig to the base setting it balances the stick to centered and the mast track is straight.

 

This, except I always measure back from the  headstay fitting and mark the deck with a grease pencil to give me the spot to pull the halyard to when I check for column. Stanchions and other fixed deck marking may or may not be symmetrical... YMMV :)

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2 hours ago, Bump-n-Grind said:

This, except I always measure back from the  headstay fitting and mark the deck with a grease pencil to give me the spot to pull the halyard to when I check for column. Stanchions and other fixed deck marking may or may not be symmetrical... YMMV :)

Measure twice, cut once....

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during sailing: look up the masttrack and see if you like the bend... (to me the slack is not alarming (on dragon's it's much worse in light air))

if i remember well it looked pretty much the same on the j35 i crewed on (late '90s (again if i remember well, we used the rhode island north tuning guide (there were 2 north tuning guides)))

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Dont forget also that the boat bends more on one tack.....i.e. when the access through the primary athwartship bulkhead is on the windward side, the deflection will be greater than on the other tack.

The amount varies, depending on arrangement, build quaity etc.

Expect at least 6 to 10 mm, but 2 x this not uncommon!

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Tyson, are you trying for a single all-purpose rig setup or do you plan to adjust across the wind range? 

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wahtever you do, please don't weld the shrouds into the turnbuckles ;)

 

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