Whale style Rudders

[Crikey]

This would make for an interesting fibreglas mod...
http://www.thedailysail.com/dinghy/12/6 ... les-rudder

32% reduction in drag,
8% improvement in lift
40% increase in angle of attack over smooth sections before stalling

Can't argue with those numbers.

[Divecoz]

Humm if the numbers are infact spot on.. Why isn't every racer on every circuit using similar designs.. Just asking??
Give or take $750 US for a dinghy rudder?? Hummm X 2??

[Crikey]

As for the racing circuit, this is where they probably came from.
So as to price, waaay too expensive for a bunch of plastic bumps!
Does the math lie?

[Steve K]

I read some stuff about this a few months ago. The article said that even aircraft will have leading edges of wings like this in the future.
Who knows?
Bill Gates said, over ten years ago that we'd have cell phones that you'd just have to touch together, to transfer files or make payments.... and where are those ................. Wait a minute............

I was thinking of building my new rudder with this configuration, IF I can get the math right. Still thinking about it.

At the least, it would be a great conversation piece.

Best Breezes,
Steve K.

[mastreb]

Just copy the design in the photo. It's showing the leading edge curve geometry. Trace that photo in sketch up, loft it to 3D on a 0012 curve, export to STL and you're ready to 3D print it.

Or make a silicon RTV mould of the current rudders, cast them in HDPE, and carve the leading edge to match the photo.

Seems like a pretty simple reverse engineering job to me...

[Crikey]

I thought of fabricating a thin wet-suit type sleeve (Divecoz?) to tightly slip over the existing rudder blades. They would have a 'spongy, bumpy' leading edge, emulating the whale fin and have a sleek surface finish for low drag.
It could be called a 'MacGregor Rudder Condom'.
Must have something to do with avoiding the breakup of the laminar flow when turned off straight ahead?
R.

[Divecoz]

OK OK Layman's language Please!!!!
The biggest issue as I see it is "The Bulb".. So we have a rudder or DB.. Dagger board would work at any length but I feel a swing keel would ONLY work full extended.. .. Anyway.. So I would need to add a solid Bulb ( sausage) to the entire length of the leading edge and that bulb, it needs as well to be tapered from the middle to the top and then again middle to the bottom.. Then to look like what a whale has? I need to "Hole Saw" at an angle from inboard to outboard / leading edge.. How do I figure those angles. Get the first one to work properly then I, as many of you do, have access to a CNC Vertical lathe. Now To Make It Easy and cost effective? Is there a material that could be purchased in " Plank Form" ? That would have the strength after machining to use as rudders? Though it would be a mass.....multitude, of other issues could not a DB on a smaller / Thinner scale be incorporated as well?

Just copy the design in the photo. It's showing the leading edge curve geometry. Trace that photo in sketch up, loft it to 3D on a 0012 curve, export to STL and you're ready to 3D print it.

Or make a silicon RTV mould of the current rudders, cast them in HDPE, and carve the leading edge to match the photo.

Seems like a pretty simple reverse engineering job to me...

[Divecoz]

Hahahaha Seriously though .. It would just fold over and unless glued to the surface in time it would work its way, all the way around to cause the opposite effect.You could cover it with Kevlar as we do for knees pads and loading pads for spearguns but it still wouldn't like living in water let alone Salt water 24/7/365

I thought of fabricating a thin wet-suit type sleeve (Divecoz?) to tightly slip over the existing rudder blades. They would have a 'spongy, bumpy' leading edge, emulating the whale fin and have a sleek surface finish for low drag.
It could be called a 'MacGregor Rudder Condom'.
Must have something to do with avoiding the breakup of the laminar flow when turned off straight ahead?
R.

[TAM]

Am I the only one that sees these as a nice way to slice through fishing line and crab pot buoys?

They do look interesting. Better grip would make for easier sailing.

[Divecoz]

I guess so, because there is really no, knife edge, to these units. Though they sure look like some kind of ginsu serrated blade on Steroids

Am I the only one that sees these as a nice way to slice through fishing line and crab pot buoys?

They do look interesting. Better grip would make for easier sailing.

[Steve K]

Just copy the design in the photo. It's showing the leading edge curve geometry. Trace that photo in sketch up, loft it to 3D on a 0012 curve, export to STL and you're ready to 3D print it.

Or make a silicon RTV mould of the current rudders, cast them in HDPE, and carve the leading edge to match the photo.

Seems like a pretty simple reverse engineering job to me...

mastreb to Earth,

We don't got no 3-D printers, CNC machines and such down here.......Shoot! I don't even have access to a 6 foot bed plotter anymore, like I use to........ just some foam and a cheese grater.

I do have some good foil templates, I made years ago, though.

You're right though, it shouldn't be that hard. Just need some time to actually try it. I'll be building my new rudder (whether or not it's a whale fin type) by laying up over a foam core glued to a post (no sure what I'll use for the post yet).

BB,
SK

[mastreb]

mastreb to Earth,

We don't got no 3-D printers, CNC machines and such down here.......Shoot! I don't even have access to a 6 foot bed plotter anymore, like I use to........ just some foam and a cheese grater.

This is mastreb, transmitting from planet Earth... do you copy?

http://makerplace.com/

$150/mo. and you can have it all: CNC routers, 3D printers, old school machine shop, wood shop, including a paint shop and industrial sewing machines and embroiderers. I've got a membership there currently to CNC route the ribs for the wing sail project I'm working on. Great place!

[Steve K]

If I had that kind of dough, I'd just call the guys and have one custom built.

This is mastreb, transmitting from planet Earth... do you copy?

You took that comment in the humorous way I intended.
I thought after sending maybe I shouldn't have said that.

BB,
SK

[Ixneigh]

Just make the leading edge serrations out of foam and fiberglass and glue them onto the.rudders. or, kill a whale, use its fins for rudders and sell the rest to the Japanese. Darn whales landing on people's boats, got too many of em anyway :;)
Ix

[Divecoz]

Well Ix. I like the first sentence anyway hahahahahaha

Just make the leading edge serrations out of foam and fiberglass and glue them onto the.rudders. or, kill a whale, use its fins for rudders and sell the rest to the Japanese. Darn whales landing on people's boats, got too many of em anyway :;)
Ix