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Vincent DePillis

Member Since 19 Jan 2005
Offline Last Active Today, 04:51 AM
*****

Posts I've Made

In Topic: Coolboats to admire

22 February 2017 - 01:20 AM

The dix boat has a lifting bulb keel!  Looks very sweet, if maybe a little fragile?   I like the Square top version.   Love the wood interior.


In Topic: Corsair Running Backstays

19 February 2017 - 01:08 PM

Tucky- not sure about Raw rig details.

Mizzmo- my guess, based on a few anecdotes and absolutely no theoretical grounding, is that a straight forestay will be usefully more efficient than a properly cut sail on a slack forestay. I tried to get an answer on this on boat design.net, but did not get a definitive response. But the other issue is that on a three wire rotating rig, the forestay sag varies with wind speed- a lot. So your design job shape will always be a compromise.

In Topic: Corsair Running Backstays

16 February 2017 - 08:00 PM

Found pic of Raw 30, looks like running back goes to outboard end of rear beam.  


In Topic: Corsair Running Backstays

16 February 2017 - 06:13 PM

Sail-- on the Raw 30, do running backs go to transom?   Pix?  When you say "chainplates too far forward" not sure what you are saying-- on the F31, the chainplates already take the shrouds, and they are not that far aft of the mast.

 

Tucky-- you mean the three points of tension are forestay, windward shroud, and windward running back, right?  Leeward shroud always gonna be slack, even w running backs, right?   Runnning backs at outboard end of aft beam might work, but  I think it would take a lot more force to get the same effect on the forestay than if you run to transom.


In Topic: Corsair Running Backstays

13 February 2017 - 11:21 PM

I have contemplated installing running backs on my F31 many times, and never gotten around to it.   My goal would be to get control over forestay sag.  It would be really nice to be able to have a twisted off main without at the same time bagging out the forestay.  

 

I have the Omohundro mast with the Jesus shackle, and Dux shrouds and forestay .   I am thinking of luggage tagging a running back onto one of the shroud thimbles at the jesus shackle, and running it to transom.  Use lo friction rings to create a 2:1 purchase, and lead purchase to spin winch on cockpit combing.    Have to reinforce attachment point obv. 

 

Be easier to run it to spin block at intersection of aft beam and float, but I don't think the angle of pull would be near as efficient in tensioning the forestay.

 

Any of you crazies ever do or consider such a thing? .