Rudder shape ?
Rudder shape ?
What is considered the best shape for a Rudder blade ?
The Rudder blade on Sprint, which I assume is same for all Minisails, the leading edge is angled back from vertical, quite a bit actually, I have altered angle of mine so it is almost vertical.
Class legal issues do not apply, I will make blade "shape" and length width etc considered most efficient.
The Rudder blade on Sprint, which I assume is same for all Minisails, the leading edge is angled back from vertical, quite a bit actually, I have altered angle of mine so it is almost vertical.
Class legal issues do not apply, I will make blade "shape" and length width etc considered most efficient.
Re: Rudder shape ?
don't know the answer but I did think this looked rather exotic -
http://www.ebay.co.uk/itm/Fixed-rudder- ... 3aaf461c7e
http://www.ebay.co.uk/itm/Fixed-rudder- ... 3aaf461c7e
Re: Rudder shape ?
The current fashion seems to be vaguely like that but with the tip under the centre of the board so that there's a reverse curve in the trailing edge.
Re: Rudder shape ?
Nigel, could be useful for dealing with fishermen.
I am sure I read somewhere the Rudder blade should be no more than 2 thirds of centre/dagger board ?
I am sure I read somewhere the Rudder blade should be no more than 2 thirds of centre/dagger board ?
Re: Rudder shape ?
On a boat like the MS, a simple rectangle will be fine, and far easier to make a nice cross section, which is where the current rudder is very poor.
Rupert
Re: Rudder shape ?
Hornet 191 Shoestring,
Hornet 595 Demon awaiting restoration
Hornet 610 Final Fling
Hornet 353
Hornet 595 Demon awaiting restoration
Hornet 610 Final Fling
Hornet 353
Re: Rudder shape ?
Wow, figures look impressive.
Re: Rudder shape ?
My Wooden Sprite rudder fits the pintails on the Monaco Minisprint hull, but I can't remember what the rudder tiller was like when I had a Minisprint 11 but would make an uneducated guess that they are the same.
Re: Rudder shape ?
trebor wrote:Wow, figures look impressive.
but..... they seem to be quoting research on the fin "tubercules" (i.e the whale fin) rather than testing the "Turbocle" rudder's performance directly
I cannot see why increasing the surface area would reduce straight ahead drag but someone with your skills should be able to knock up a blade easily enough and do some testing - that is the only way to find out really
Re: Rudder shape ?
If you look more closely I'm not entirely convinced that all the things they quote translate into advantages on the race course. For instance being able to put the rudder over harder before it stalls may actually be slower rather than faster because of all the extra drag from the rest of the hull if you turn too fast. We already know that in most circumstances people over use rather than under use the rudder.trebor wrote:Wow, figures look impressive.
Re: Rudder shape ?
The only independent discussion was on the y and y forum In 2012, the consensus was, needed more testing, manufacturer claims narrower blade achieved with this design, due to reduced cavitation
Last edited by trebor on Tue Aug 11, 2015 5:59 pm, edited 1 time in total.
Re: Rudder shape ?
There is one I know of being used on a Hornet, probably not a large enough sample to be useful but they were positive about it. They probably would have to be as they own 50degree sailing.
Hornet 191 Shoestring,
Hornet 595 Demon awaiting restoration
Hornet 610 Final Fling
Hornet 353
Hornet 595 Demon awaiting restoration
Hornet 610 Final Fling
Hornet 353
Re: Rudder shape ?
The basis of this design, is taken from nature, the humpbacked whales fins are substantially narrower than other marine creatures of comparable size (Dolphin, Shark etc).
I wonder how many they have sold ?
The designs been out there for a long time now, are their any newly designed dinghies using it?
I know a lot of classes would not be able to use this rudder shape, but their are plenty of classes with out restrictions.
One of the contributors on y&y forum said this would be ineffective below 5 knots and would probably be slower, also ineffective above 30 knots, thats me out then
I wonder how many they have sold ?
The designs been out there for a long time now, are their any newly designed dinghies using it?
I know a lot of classes would not be able to use this rudder shape, but their are plenty of classes with out restrictions.
One of the contributors on y&y forum said this would be ineffective below 5 knots and would probably be slower, also ineffective above 30 knots, thats me out then
Re: Rudder shape ?
I am going to try Tubercules, combined with a Chord.
I hope I will not be breaching someones patent ?
I hope I will not be breaching someones patent ?
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Re: Rudder shape ?
Don't think Mother Nature takes out patents....trebor wrote:I am going to try Tubercules, combined with a Chord.
I hope I will not be breaching someones patent ?
Matt
Int Moth K2992
Int Moth K2992