New Posts New Posts RSS Feed: Gybing Plates
  FAQ FAQ  Forum Search   Register Register  Login Login

Gybing Plates
 Post Reply Post Reply Page  123 7>
Author
  Share Topic Share Topic  Topic Search Topic Search  Topic Options Topic Options
iGRF View Drop Down
Really should get out more
Really should get out more
Avatar

Joined: 07 Mar 11
Location: Hythe
Online Status: Offline
Posts: 6499 		Post Options Post Options   Quote iGRF Quote  Post ReplyReply Direct Link To This Post Topic: Gybing Plates
    Posted: 26 Jan 16 at 11:08am
I don't suppose anyone might have a picture of one, I'm trying to fashion the head of the plate in this Minisprint I bought recently and doing it from memory, ahem thirty five year old memory at that, last time I had one was in 1981 and it wasn't particularly successful in a div 2 board, I'm hoping the additional weight and leverage of this Minisprint with it's canoe seat might be able to overcome the excess lift they generate.

Snow Equipment Deals    New Core Kite website
Back to Top
davidyacht View Drop Down
Really should get out more
Really should get out more


Joined: 29 Mar 05
Online Status: Offline
Posts: 1345 		Post Options Post Options   Quote davidyacht Quote  Post ReplyReply Direct Link To This Post Posted: 26 Jan 16 at 12:10pm
Have a look at 

http://www.int505.org/old_site/eck1.pdf
Happily living in the past
Back to Top
davidyacht View Drop Down
Really should get out more
Really should get out more


Joined: 29 Mar 05
Online Status: Offline
Posts: 1345 		Post Options Post Options   Quote davidyacht Quote  Post ReplyReply Direct Link To This Post Posted: 26 Jan 16 at 12:15pm
Do you have access to Autocad?  I have some drawings that I did for my N12 with the gybing head sections and profiles in a DWG or DXF format.
Happily living in the past
Back to Top
iGRF View Drop Down
Really should get out more
Really should get out more
Avatar

Joined: 07 Mar 11
Location: Hythe
Online Status: Offline
Posts: 6499 		Post Options Post Options   Quote iGRF Quote  Post ReplyReply Direct Link To This Post Posted: 26 Jan 16 at 12:31pm
Regretably no access to autocad, but that's told me one thing I needed to know, the gybe angle, no more than 4 degrees, I think that's where I may have gone wrong before I seem to remember 7 degrees.

Fascinating document it advocates gybing plates without question and suggest jib angles can be altered, not that that's relevant in my case, but this little boat allegedly is not know for its' pointing capability, but that's hardly surprising if you could have seen this plate before I took a belt sander to it. it was just a parallel sided blunt both ended slab of wood, I'm even surprised they glass sheathed it.

Thanks for posting that, so do we know if 5 ohs still use gybing plates? With all this assym nonesense of recent years they must have well gone out of fashion.

Edited by iGRF - 26 Jan 16 at 12:32pm
Snow Equipment Deals    New Core Kite website
Back to Top
Roger View Drop Down
Really should get out more
Really should get out more
Avatar

Joined: 23 Mar 04
Location: Somerset
Online Status: Offline
Posts: 524 		Post Options Post Options   Quote Roger Quote  Post ReplyReply Direct Link To This Post Posted: 26 Jan 16 at 12:54pm
Originally posted by iGRF



Thanks for posting that, so do we know if 5 ohs still use gybing plates? With all this assym nonesense of recent years they must have well gone out of fashion.


Pretty much standard in all new 505s, and a lot of older boats converted to take them.

There is loads of stuff written about it, but from memory 3 deg is what is currently in use, and a lot of 505 boards use stoppers to stop the board gybing when it is lifted, although there are some that put the boats fully down on all angles of sailing and leave it there.

http://www.int505.org/old_site/gybecb.htm

One point of caution is that a gybing board will load up the sides of the certerboard case more than a conventional board, and certainly in some older 505s which have converted to gybing boards they have felt it necessary to beef up the case.
Back to Top
JimC View Drop Down
Really should get out more
Really should get out more
Avatar

Joined: 17 May 04
Location: United Kingdom
Online Status: Offline
Posts: 6662 		Post Options Post Options   Quote JimC Quote  Post ReplyReply Direct Link To This Post Posted: 26 Jan 16 at 12:57pm
There are several classes that use gybing boards, but in many of them only some boats have them. According to my theorising the angle of the board should match the 'leeway' angle the boat would take up with a non-angled board, so a boat with a hideously inefficient board would do best with more angle than a boat with an optimal one. But there are so many opinions about the things...
Back to Top
Phil_1193 View Drop Down
Groupie
Groupie


Joined: 07 Jan 10
Online Status: Offline
Posts: 78 		Post Options Post Options   Quote Phil_1193 Quote  Post ReplyReply Direct Link To This Post Posted: 26 Jan 16 at 1:54pm
Originally posted by davidyacht

Do you have access to Autocad?  I have some drawings that I did for my N12 with the gybing head sections and profiles in a DWG or DXF format.


Originally posted by iGRF

Regretably no access to autocad........


I maybe telling your granny etc but Autocad files can be 'printed' in PDF and saved/ sent as such

Option 2 is download DWG True View from the AutoCad website, its a free CAD viewer that allows zoom and pan, turn off layers, take measurements etc to the same levels as AutoCad so makes details easier to read
Back to Top
iGRF View Drop Down
Really should get out more
Really should get out more
Avatar

Joined: 07 Mar 11
Location: Hythe
Online Status: Offline
Posts: 6499 		Post Options Post Options   Quote iGRF Quote  Post ReplyReply Direct Link To This Post Posted: 26 Jan 16 at 2:52pm
You need to translate all that into Apple speak, not sure if there's much in the CAD world that comes without considerable expense.

Edited by iGRF - 26 Jan 16 at 2:53pm
Snow Equipment Deals    New Core Kite website
Back to Top
davidyacht View Drop Down
Really should get out more
Really should get out more


Joined: 29 Mar 05
Online Status: Offline
Posts: 1345 		Post Options Post Options   Quote davidyacht Quote  Post ReplyReply Direct Link To This Post Posted: 26 Jan 16 at 4:09pm
Originally posted by Phil_1193

Originally posted by davidyacht

Do you have access to Autocad?  I have some drawings that I did for my N12 with the gybing head sections and profiles in a DWG or DXF format.


Originally posted by iGRF

Regretably no access to autocad........


I maybe telling your granny etc but Autocad files can be 'printed' in PDF and saved/ sent as such

Option 2 is download DWG True View from the AutoCad website, its a free CAD viewer that allows zoom and pan, turn off layers, take measurements etc to the same levels as AutoCad so makes details easier to read

There was a level of how helpful I was intending to be, and do my day job!

In essence our board had a diamond shaped head, which was slightly thrupenny bitted at the shoulders.  It worked fine.  My experience was that the biggest gain was by sailing slightly free, relative to how high you could point, but being really powered up, so in the 12's the biggest gain was if you were heavier, rather than lighter and feathering.

My suggestion to GF would be to make a template of the centreboard case and of the centreboard head section and trim the head section to achieve the desirable gybe angle.

If the board was not loaded up it could slop around a bit.  I know that Ray Rouse's 14 had a device that locked the board when the board was retracted.  There is a view that the boards can "self" steer downwind, don't think that this is a problem on the run, but could be on a reach, but I never found this to be the case.

We used all of the efficiency gains of the centreboard and rudder to reduce the foil areas.  With hindsight probably a little too much, since there was a cost in getting flow going in dead boat situations.
Happily living in the past
Back to Top
gordon1277 View Drop Down
Really should get out more
Really should get out more


Joined: 24 Mar 10
Location: United Kingdom
Online Status: Offline
Posts: 665 		Post Options Post Options   Quote gordon1277 Quote  Post ReplyReply Direct Link To This Post Posted: 26 Jan 16 at 4:09pm
Hi GRF
Have a look at a free download called Trueview which allows you to view and plot CAD files.
Gordon
What a shame about all the boats lost at Cowes some peoples years of effort in restoration just gone plus classics we will never see again.
Awful for all concerned.
Gordon
Lossc
Back to Top
 Post Reply Post Reply Page  123 7>

Forum Jump Forum Permissions View Drop Down

Bulletin Board Software by Web Wiz Forums® version 9.665y
Copyright ©2001-2010 Web Wiz
Change your personal settings, or read our privacy policy