Rudder Profiles

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colinbrown
Posts: 98
Joined: Tue Jun 02, 2009 8:22 pm

Rudder Profiles

Post by colinbrown » Wed Sep 07, 2011 6:56 pm

Building a new rudder for GBR 319, propose to use the tried and tested NACA 000 series. Can anyone suggest a better section , that is of course that I can make at home with normal tools?
Size will be 535mm deep by 200mm x 20mm. Views please :lol:

Mike Rowe
Posts: 28
Joined: Thu Jul 17, 2003 11:41 am
Location: United Kingdom

Re: Rudder Profiles

Post by Mike Rowe » Wed Sep 07, 2011 7:34 pm

Hi Colin

I'd say a NACA 00 series was probably as good as any. The maximum thickness is fairly far forward and it has good resistance to stall which is essential for a rudder. The last thing you need is it stalling in a manoeuvre. You probably need it a little fatter to get the rudder shaft in, maybe?

Different kettle of fish for a daggerboard of course, which will always be operating at low angle of attack, so the most important feature is lowest drag at the small incidence.

Mike

PS I've not forgotten y'all

colinbrown
Posts: 98
Joined: Tue Jun 02, 2009 8:22 pm

Re: Rudder Profiles

Post by colinbrown » Thu Sep 08, 2011 7:17 pm

Cheers Mike, as you say , for the centreboards I use a NACA 63 000 SERIES, which has a finer entry and moves the max thickness back to 35%. I have tried a rudder with the NACA 63 000 series , on my old yellow AC but it stalled out on fast reaches with the kite, not nice. I used that rudder in Germany but again found that tacking was a problem in windy weather. I'm now starting to make 2 rudders if different sizes for the new Morrison. Wonderful machine, scares me whitless !

Mike Rowe
Posts: 28
Joined: Thu Jul 17, 2003 11:41 am
Location: United Kingdom

Re: Rudder Profiles

Post by Mike Rowe » Thu Sep 08, 2011 10:26 pm

Hi Colin

I used NACA 64000 on my daggerboards, but either way, a finer entry works on the board but not rudders. Good luck with the Morrison. When do you add the kite?

Mike

colinbrown
Posts: 98
Joined: Tue Jun 02, 2009 8:22 pm

Re: Rudder Profiles

Post by colinbrown » Fri Sep 09, 2011 11:57 am

The standard canoe without the kite is just fine. Not at all sure I would want to encourage kites on the new rules canoes. I think we need a good take up of new younger owners first, real need to keep costs down ,kite adds considerably to the cost. With the proposal to increase minimum weight to 55kgs will mean that ply boats can be built of nearly nothing and be competitive. Steve Clark ( USA ) built 2 in 3 months ! They also look fantastic

Steve Clark
Posts: 165
Joined: Fri Aug 01, 2003 2:26 pm

Re: Rudder Profiles

Post by Steve Clark » Fri Sep 09, 2011 2:56 pm

They took a bit longer than 3 months to build. More like 6, but I'm working on some things to shorten that up and make the results more repeatable.
New system will also make foam/carbon hulls possible as well.
On rudder sections, I have used all sorts. The most recent have been NACA 63010. This seems to be the consensus section for near surface foils. It is used on surfboard/ sailboard skegs and catamaran rudders for example because it seems to be very resistant to sucking air down the low pressure side.
I like relatively thin sections and deep blades, so using Nitronic 50 ( yacht rod rigging scrap) for the shafts is necessary if one wants to keep the shaft diameter down to 12mm or so.
SHC
Beatings will continue until morale improves

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