A few misc things

[Ethan Petersen]

First: Marc, welcome to the class!  Building the boat is a great project, and when you are done it is an excellent boat.  If you have any questions during the build, there are several experts on this group that are happy to help.

Second:  Philip, what is class minimum weight?  I don't know where the class rules are.  I have never weighed my boat and probably should, I am curious and people keep asking me.  Does the rule spell out the 'measurement trim'?  I assume the weight is without sails, and some of the running rigging removed, but that gets complicated on this boat.

Finally: I am trying to sort out some main sail trim stuff.  I have the regular Banks main sail, and it looks like the batten pockets are too loose.  If I tighten the battens enough to not have vertical wrinkles in the sail when the cunningham is on, then the battens always try to pop the sail to one side.  Has anyone else had this problem?  Can I fix it by having a sailmaker flatten out the batten pockets to take the slop out?

Ethan

[Philip Ryan]

Ethan - I'll have to check on the weight question for accuracy but in general, the weight is something like 175 lb and is measured with spars and blades, but no sails or spin sheet. If you haven't heard from me on it in a couple of days, please remind me.

As for vertical wrinkles, the banks set up seems to always have some vertical wrinkles in the front half of the sail, and the batten pockets are always wrinkled on the windward side of the sail. The battens should be just snug in the pocket, not tight. Snug enough to stay in when the sail is flogging.

If everything is good but you are getting wrinkles when you crank the cunningham, flat enough for the battens to pop to leeward when sailing, and or the lower batten has a bit of an s shape to it, (i.e. very heavy air settings) then these characteristics are normal if not right. The fit of the sail and the mast was never worked out in very great detail, so the luff curve and the mast bend characteristics only match each other in an approximate way.

I have found that when using different sails on the same mast and the same sail on different masts, that there is usually only one draft/power setting at which the sail sets nicely, and everything else is a compromise. To make matters worse, that setting is different with every sail and mast.

It is a known variable that the masts have been getting stiffer over the years, but nobody talks about how every Banks sail was different too. So I just litter the sail with tell tales, and work out every setting any time I switch sails or masts. However, the most common mistakes are to have too much bend in the lower mast, to not use enough cunningham, using too much vang, and have shrouds too loose. I'm a detail oriented guy, so the slight mis-matches in the gear bother me until I decide that my goal is to find the best average shape for the conditions I am in. Once I'm in that mind set, wrinkles don't really matter much

I hope this helps - Philip

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[Philip Ryan]

OK - I had time to look it up. 

The hull weight is 77kg/170lbs. It includes everything except the main sheet and spin sheet, foils, mast and boom, and sails.

In other words, the spin pole and the rudder cassette assembly are included in the weight.

I can't remember why or where the information was, but when we measured the boats in Alamitos, the spars and foils were included on the boat. I haven't read through the rules in a few years now. Maybe we were just checking all-up sailing weight.

[Ethan Petersen]

Spars are not included in the weight, seems weird, and is going to make it a pain to weigh.  I generally don't trailer my boat anywhere so it is not well set up for removing all the rigging.

Oh-well, maybe I'll weigh it after de-rigging it to trailer it to Nationals this summer.  We'll see.

Thanks for the comments on the main trim.  It'll inform my tweaking of the tuning.

Ethan 

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[Philip Ryan]

Yep - and the tweaking that you come up with will only apply to your mast, your sail and your body weight. I always start with getting the main shroud tension right by getting the jibstay sag "even". I think of it like mast bend. I.e. the jib is cut to work with a specific amount of head stay sag  which is determined by your main shroud tension which is influenced by your body weight on the trapeze wire.

Once I've worked my way through all the adjustments, I usually start over and refine it a couple more times before I'm satisfied that the boat is quick.

It seems to work for me, I hope it helps. Ping me with more questions if they come up.

If I get some time I'll read through the rules and see if there is a weight with spars listed, and try to find that most recently updated rules that we did a few years ago and e-mail it to you. - Philip -

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