DaveOnCudjoe Posted April 4, 2012 Posted April 4, 2012 Mike, With reguard to routing the outhauls. I'll laminate some strips to shape and separate them with spacers much like a gunwale would look and route the lines through the spacers. I want all reefing functions at the mast so I visualize reefing like this, release halyard, slack downhaul and move to new tack, tighten halyard and tension downhaul. Rather than move the sprit I'll have a line to the new clew rigged so I'll slack the snotter, pull in the new clew with a line not in tension and then tension the snotter. The lines running through the sprit will only be hauled in or slacked will under no load and I hope will move smoothly through holes(fairleads) in the spacer blocks. This is new territory for me and very much under developement. I'm going from aluminum to carbon fiber masts and also want to carry the rig lower than the stock Pearl layout. A quick look at the yahoo Sea Pearl home page and the Core Sound 20 photo on the B&B sight demonstraits what I'm trying to achieve. Dave Quote
tom151 Posted April 4, 2012 Posted April 4, 2012 [snip]...the stuff that keeps it from sagging will add some weight but a single will likely be marginally lighter weight. I think some inventive thinking will be needed for a wishboom on a roatating wing mast. The over rotation will need a very wide space between the booms near the mast. Tension between the snotter and clew will tend to limit mast rotation. I cannot immediately see any way to mount a wishboom directly to a rotating wing mast since the over rotation needed for best performance would then not be possible on the wingmast.. Tom, thanks again for the added details. About marrying the wishbone booms to a rotating wingmast, don't know if this is inventive thinking, but here it is... The chord dimension is part of the problem, so I looked for a wing shape of small chord proportions. The masts I settled on will be masts similar in shape to the Taser masts, as I am going to trust Bethwaite that a relatively small mast chord mast of approx 3.0" thickness x 5.05" chord of the appropriate shape will work (as his experimental work showed, and from which the Taser section was developed). And this particular mast shape does not require as much over-rotation with respect to the soft sail segment in order to deliver it's full performance. The other problem, fixing the wishbone to the mast, has to do with the counter rotating moment of the snotter against desired the mast rotation. I do plan on having a dedicated mast rotater but do not want this to be highly loaded (been there, done that), so, to your point, i hope to minimize the snotter to mast induce moment. I am going to try using a circular bale (like an old fashioned boom bale, but circular, not U shaped) to allow the snotter tackle to rotate to a position that at least reduces the adverse moment arm as the mast rotates inside the wishbone - as much as I can, that is. Don't know if this word picture was clear enough for you to comment - but any critique or additional thoughts will be greatly appreciated. Thanks, TomH Quote
Peter HK Posted April 4, 2012 Posted April 4, 2012 The masts I settled on will be masts similar in shape to the Taser masts, as I am going to trust Bethwaite This brings back memories. I remember going to a Tasar masterclass with Frank Bethwaite in the 1980's... this was at the Gold Coast just south of Brisbane. There was a group of dinghies on the beach to which people were assigned. A short race then followed. Frank was with us on the first one advising how to tune the boat...we were well ahead. When he moved onto the next boat in the next race we didn't do so well I always remember the Tasar as awfully efficient. As you say the rotating mast was relatively small. Cheers Peter HK Quote
Tom Lathrop Posted April 4, 2012 Posted April 4, 2012 Clear enough Tom. I had thought of a circular something but the size was rediculous. The small chord makes it much simpler. Good luck and let us know how it goes. If the boat is really fast (why else go to a wing mast?), there is no need for a boom and the angle of attack will always be small. The main will never be let out very far, so no boom needed and full length battens will do as well. Quote
Scott Dunsworth Posted April 4, 2012 Posted April 4, 2012 Tom I am planning on building aluminum wishbones for my 28. I have been wondering about something other than rigging them. I assume they will be of an alloy of 6061 T6 but don't know for sure yet. My question is when they are welded up the heat generated to make the weld will take the temper from the alloy in the joint area. What do you think? Scott Quote
Tom Lathrop Posted April 4, 2012 Posted April 4, 2012 Tom I am planning on building aluminum wishbones for my 28. I have been wondering about something other than rigging them. I assume they will be of an alloy of 6061 T6 but don't know for sure yet. My question is when they are welded up the heat generated to make the weld will take the temper from the alloy in the joint area. What do you think? Scott Likely true Scott, but I know of many masts in this alloy that have been welded to create taper over a length of several feet and they still worked ok. I'm not an expert on welding. Quote
DaveOnCudjoe Posted April 22, 2012 Posted April 22, 2012 As I continue to develope my curved sprits I remember an occasion where an unintentional gybe resulted in a broken sprit on Green Heron. My masts will be able to rotate in their socket but should I take additional steps in design to protect the sprits? Dave Quote
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