|
|
Post by comprendre on Jul 20, 2012 18:33:38 GMT
I have purchased an SO37. The boat sails very well and the PO took great care of her, but there are a few things I am uncertain about. One is standing rig tension.
Would anyone happen to have Loos Gauge measurements for their rig...?
I am interested in cap shrouds, intermediate shrouds, lower shrouds, and baby stay.
|
|
|
|
Post by rene460 on Jul 21, 2012 11:28:15 GMT
Hi Comrendre! I had similar concerns with my SO30. I found the Selden rigging guide very useful, though tensioning everything to their recommendations feels a bit extreme. A few main things to achieve. Check if mast rake is something reasonable, check that it is straight from side to side, and an even curve from top to bottom when viewed side on, mid height forward, I.e. no reverse bend. Max bend must not exceed mast makers recommendation, usually about half mast fore-aft dimension is about right. Then when sailing check that lee shrouds do not go slack in heavier weather. If all looks ok, leave well enough alone. Be aware if you change tensions, you need to recheck engine to shaft alignment as rig tensions are more than enough to bend the boat, then you will have problems with vibration, and cutlas bearing wear. In principal rig tension should be same on each side, but if mast is straight, they must be within tolerance. I have so far found no more information than this, but the sail maker and a local rigger both checked the rig and did not want to make any changes. The mast curve should be about what the sail maker expected when designing the luff curve, otherwise sail will be too deep or too flat. I hope that this helps
Rene460
|
|
|
|
Post by davideso37 on Jul 22, 2012 14:31:38 GMT
|
|
|
|
Post by comprendre on Jul 23, 2012 0:10:48 GMT
Thanks gents. I was hoping to get away with a few spot checks, but no sense in taking short cuts. Thanks a bunch for the intel.
|
|
|
|
Post by davideso37 on Jul 23, 2012 12:21:33 GMT
Comprendre, The first thing I did with the standard SO37 was to put on an adjustable backstay and then set the backstay tension for the desired luff sag. Our SO37 had a lot of mast bend which was right for the mainsail luff curve so tight uppers and baby stay. The fuller you want the mainsail the tighter you tension the lowers and intermediate. When hard on the wind the leeward shrouds should be loose but not flopping about. The foot of the genoa should be able to pull the shrouds to windward a little. Some very useful tuning guides are on the Beneteau 36.7 class web site. www.beneteaufirst367.org/page.php?id=11#It is a similar sized yacht with sail area more like the SF37 but close enough to get some ideas. Regards David |
|
Toby
Junior Member
Posts: 12
|
Post by Toby on Aug 2, 2012 5:59:51 GMT
Hi comprendre and davidso37, do your boats have a turnbuckle to adjust the forestay tension? Mine seems to be fixed, without turnbuckles. There is no turnbuckle under the furler drum either. I'm having some trouble with my facnor sd165 genoa furler going hard for a while now. Tried to adjust the forestay, but no turnbuckle. So I'm going to do a few turns on the backstay to see whether it helps. Otherwise I always need some gentle support from a winch to get the first 30-40% of my 135% genoa in.
By the way, my leeward shrouds are loose, which means under load (close hauled about 20 knots apparent wind) I could move them about 2 cm from side to side through their normal line. Is this what you define as flopping?
cheers, toby
|
|
|
|
Post by davideso37 on Aug 7, 2012 13:17:55 GMT
Toby,
The original rig had a fixed forestay and all the tension adjustment was done via the cap shroud and backstay.
I did put an adjuster on the forestay but only because we changed the rig and we could not calculate the exact length for the forestay. That said the forestay turnbuckle is inside the furler which we had to modify with a special turnbuckle tube. If we do need to adjust the forestay we need to drill out the rivets in the furler telescopic section and pull the furler up the forestay, do the adjustment and then re pop rivet the telescopic sections. I hope you get the idea that this is not a simple task and best done by a professional rigger so we do not adjust the forestay length for different conditons.
Do as many turns on the backstay as you feel needed to tighten the forestay when racing but remember that this will release some tension from the cap shrouds which may need re tensioning. With the backstay re released to check the cap shroud tension it should not be more than 20% of the breaking strain. That is a maximum stretch of 4mm over a 2 metre length.
I would not be worried about 2cm wobble in the leeward shrouds in 20 knots.
When you say the Facnor SD165 is going hard I can tell you that the plastic bearing wear out and can fall out. I have replaced all mine and it made a big difference. Again it is a riggers job unless you are pretty handy and have done it before. You need to take the forestay off to work on the joins as the bearings go at each join. The screw are pretty tight as they are sealed in with loctite so it is easier if everything is flat on the ground. Talk to your local Facnor agent. Ours is very helpful and we have always received parts promptly and for a very modest cost.
Regards
David
|
|
