messing with design

I have plans for WR180 and North Bay both of which seem to be troublsome in waves because of low hull rocker. Being in Australia these plans represent good value to me. Is it possible to increase the rocker of either of these craft simply by curving the lines of where the bottom pannels meet in the centre away from the centre line towards the ends? If more wood disappears from here wouldn't the join be higher: ie like cutting away the forefoot?

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RE: messing with design

If you do not have a good design software program to plug the design into when you will change dimensions you will affect the rocker BUT I would suggest you spend the time to make a scale model of your chosen design and make scale changes to the panels these can be glued up quickly with a gap filling Cyanoacrylate (super glue) and tape stitches to test the outcome be sure this model is carefully dimensioned and use tape accross the seams in place of stitches, you should be able to find some very thin plywood (less than 1/16th")at a local model airplane dealer to build this with remember work carefully and you will end up with a design that suits your needs but do not alter greatly either of these designs very much as they are very good now

C Fox Boat School 

www.cfoxwoodboats.com 

RE: messing with design

I built a North Bay, from plans. Mine handled well and I was very happy with it - except in following seas and (big) wind, as others have noted. A skeg would, I believe, have fixed this vice, though perhaps not always.

On my boat - unlike others, it seems - any weathercocking was easily corrected just by leaning - except in the aforementioned conditions, of course.

Anyway, there's an article in the summer 2006 Masik newsletter, at QajaqUSA.org, about modifications to the North Bay. You might want to check it out: http://www.qajaqusa.org/newsletter/Masik_Summer_2006_Vol3No4_v3.pdf

 Good luck! DaveMy North Bay

 

 

RE: messing with design

The skeg on the Northbay helps, but it doesn't fix the problem.  I think most weathercocking is fairly easily corrected with leaning and stroke correction, but I can see how that could get tiring for people.  Another option might be to add one of the skeg/rudders, which are retractable skegs that also pivot like a rudder.  I saw a link to them recently but I'm not sure if it was on here or somewhere else.

 

Revensdale: honestly I wouldn't expect to get a lot of change from the design as there's not a lot of room to make mods in the hull shape without truly redesigning the hull.  I did post a question a couple months back about a "Northbay 2" or something like that, and someone else had a similar question.  Both got some good responses, so you may want to look in the archives for the suggestions that were given in those threads.  The general concensus is that the panels don't have enough material to add the needed angle that will prevent the weathercocking.  If building from plans, it's obviously easier to accomodate that and build the panels with more outward angle and a slightly wider V in the aft hull.   It would likely require mods to both panels (sheer and keel) to accomplish that on the NB.  I haven't built a WR18 so I can't speak to that.

 

Good luck with it.

 

FrankP 

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