Fixed Rudder

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Gregg9020

Gregg9020

.
Apr 25, 2005
410
Macgregor Venture 25 My Backyard
I have a freind that has a pretty warped rudder and needs to know the dimensions of a fixed rudder. He thinks the two of us can build one for a lot less than the IdaSailor one, and might want to give it a try. I think we can do it without a lot of trouble. What I am looking for is: Overall length: Thickness: Width: Possible Weight: Thanks, Gregg
 
Gregg9020

Gregg9020

.
Apr 25, 2005
410
Macgregor Venture 25 My Backyard
1976 Mac (Venture) 25

Sorry about that, I thought that you all knew what boat I was talking about. I guess the cold here in Cali is starting to get to me.
 
Timo42

Timo42

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Mar 26, 2007
1,042
Venture 22 Marina del Rey
I have the old rudder from my 222

leaning up against my garage, is it the same or similar? Tim It is getting cold, I am actually wearing a jacket today ;D
 
Gregg9020

Gregg9020

.
Apr 25, 2005
410
Macgregor Venture 25 My Backyard
Tim...

Are you looking ro sell it? Is it in good shape? Can you send me picts? I an send you my email and we can talk. Gregg
 
Timo42

Timo42

.
Mar 26, 2007
1,042
Venture 22 Marina del Rey
Yes, yes, I think so

I can take pics this weekend. It has a few scrapes, the tiller needs to be refinished, Tim
 
B

Bob McL

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Oct 16, 2008
512
MacGregor/Venture 25 Mesa AZ
Dimensions

I checked and measured my '76 V25 and.. length = 71.25" width = 11" below bottom pintal and tapers to 7.25" at top thickness = 1.5" from bottom of lower pintal to bottom of rudder = 36" Also from about the lower pintal down the trailing edge takes on a taper. The bottom is flat - not rounded (other than the edges). It has rounded edges all around and covered in fiberglass. Have not ground into it to check but there is a small crack at the top and I will do the latter. I also will be building a new version where the rudder can swing into a fully upright position and the overall taper will be like the shape of an aircraft wing. Where is Penngrove? I used to live in Santa Rosa.
 
B

Bob McL

.
Oct 16, 2008
512
MacGregor/Venture 25 Mesa AZ
Dimensions

I checked and measured my '76 V25 and.. length = 71.25" width = 11" below bottom pintal and tapers to 7.25" at top thickness = 1.5" from bottom of lower pintal to bottom of rudder = 36" Also from about the lower pintal down the trailing edge takes on a taper. The bottom is flat - not rounded (other than the edges). It has rounded edges all around and covered in fiberglass. Have not ground into it to check but there is a small crack at the top and I will do the latter. I also will be building a new version where the rudder can swing into a fully upright position and the overall taper will be like the shape of an aircraft wing. Where is Penngrove? I used to live in Santa Rosa.
 
Gregg9020

Gregg9020

.
Apr 25, 2005
410
Macgregor Venture 25 My Backyard
Just South

We are pinched between Rohnert Park to the west and Petaluma to the south. Sonoma Mountain is on the east side of SSU, I am up on that. Things are changing around here fast. SSU is adding Dorms and we are getting three lanes on 101 through Santa Rosa. What part of Santa Rosa did you live in?
 
Gregg9020

Gregg9020

.
Apr 25, 2005
410
Macgregor Venture 25 My Backyard
Just South

We are pinched between Rohnert Park to the west and Petaluma to the south. Sonoma Mountain is on the east side of SSU, I am up on that. Things are changing around here fast. SSU is adding Dorms and we are getting three lanes on 101 through Santa Rosa. What part of Santa Rosa did you live in?
 
B

Bob McL

.
Oct 16, 2008
512
MacGregor/Venture 25 Mesa AZ
Responded

I responded via the email function on your info registration. Let me know if you get it as I am not sure that works.
 
B

Bob McL

.
Oct 16, 2008
512
MacGregor/Venture 25 Mesa AZ
Responded

I responded via the email function on your info registration. Let me know if you get it as I am not sure that works.
 
A

Arabella

Solid Piece of Oak?

I have seen some beautiful rudders made with a single piece of oak. The plans look like you could build a strong laminated rudder, but it looks like a lot of work. One thing I know is that oak would be a lot stronger, cheaper and better looking than the ida plastic rudders. One thing I suggest is not to go with the original design, extend the leading edge a bit and you won't have to fight the tiller. I was wondering about making one out of aluminum. It wouldn't have the airfoil, but I'm not convinced you would really see a performance difference, although racing experts seem to disagree, but then they weren't talking about a Mac 25. Seems to me thinner means less resistance, although I have heard you want your keel and rudder to act like a wing, but again that was for a racing boat.
 
A

Arabella

Solid Piece of Oak?

I have seen some beautiful rudders made with a single piece of oak. The plans look like you could build a strong laminated rudder, but it looks like a lot of work. One thing I know is that oak would be a lot stronger, cheaper and better looking than the ida plastic rudders. One thing I suggest is not to go with the original design, extend the leading edge a bit and you won't have to fight the tiller. I was wondering about making one out of aluminum. It wouldn't have the airfoil, but I'm not convinced you would really see a performance difference, although racing experts seem to disagree, but then they weren't talking about a Mac 25. Seems to me thinner means less resistance, although I have heard you want your keel and rudder to act like a wing, but again that was for a racing boat.
 
7

70623

.
Jul 14, 2004
215
Bristol 30 Le Roy, Mi.
Rudders

Getting a good foil using aluminum would be the easy part. Having enough strength would be the hard part. Laminated wood is much stronger and much less prone to cracking than solid wood. This is the main reason for laminating a rudder. The other is it can make shapping the rudder easier than cutting it out of a solid piece. Back to the aluminum rudder. It would be simple to wrap a form (foil shaped) with a sheet of aluminum to form a good aero (hydro) shape. The problem would be in having enough strength to take the latterial pressures and not break or bend. I have made laminated rudders for Mac's and other sailboats both by laminating vertically and the sandwich method. Using a strong (usually oak) sections at the leading edge (for strength when the rudder strikes objects) center (to take the latterial pressures) and trailing edge (because it is thin and so is the most fragile part of the rudder) and woods as soft as pine inbetween. The strongest rudders were made laminating oak and white ash. These rudders were given several coats of epoxy when finished to help keep water out of them. Teak and mahogony have more natural oils in them and won't rot as fast, but they are not as strong either. For a cheap fast layup I have used the sandwich method. Using marine plywood layed up from the center out. Then instead of planing the wood down, the steps were filled with epoxy thickened with fiberglass micro fibers. A layer (actually 2 layers over the sides) were applied of fiberglass cloth. (using epoxy to bond it) This rudder is on a North American Spirit 23' and is painted. It has already sailed from Ms. to Brownsville Tx. with no problems. This method of building a rudder only needs you to have a drill, a sander and a saw. No fancy tools. It could be made even stronger by placing a layer of fiberglass cloth between each layer of wood. Even if you end up with an Ida rudder you should at least try and make one rudder your self. It's an important part on your boat and will give you much more confidence when you go to tackle other projects on your boat.
 
7

70623

.
Jul 14, 2004
215
Bristol 30 Le Roy, Mi.
Rudders

Getting a good foil using aluminum would be the easy part. Having enough strength would be the hard part. Laminated wood is much stronger and much less prone to cracking than solid wood. This is the main reason for laminating a rudder. The other is it can make shapping the rudder easier than cutting it out of a solid piece. Back to the aluminum rudder. It would be simple to wrap a form (foil shaped) with a sheet of aluminum to form a good aero (hydro) shape. The problem would be in having enough strength to take the latterial pressures and not break or bend. I have made laminated rudders for Mac's and other sailboats both by laminating vertically and the sandwich method. Using a strong (usually oak) sections at the leading edge (for strength when the rudder strikes objects) center (to take the latterial pressures) and trailing edge (because it is thin and so is the most fragile part of the rudder) and woods as soft as pine inbetween. The strongest rudders were made laminating oak and white ash. These rudders were given several coats of epoxy when finished to help keep water out of them. Teak and mahogony have more natural oils in them and won't rot as fast, but they are not as strong either. For a cheap fast layup I have used the sandwich method. Using marine plywood layed up from the center out. Then instead of planing the wood down, the steps were filled with epoxy thickened with fiberglass micro fibers. A layer (actually 2 layers over the sides) were applied of fiberglass cloth. (using epoxy to bond it) This rudder is on a North American Spirit 23' and is painted. It has already sailed from Ms. to Brownsville Tx. with no problems. This method of building a rudder only needs you to have a drill, a sander and a saw. No fancy tools. It could be made even stronger by placing a layer of fiberglass cloth between each layer of wood. Even if you end up with an Ida rudder you should at least try and make one rudder your self. It's an important part on your boat and will give you much more confidence when you go to tackle other projects on your boat.
 
walt

walt

.
Jun 1, 2007
3,511
Macgregor 26S Hobie TI Ridgway Colorado
foil shape

This web site seems to have some good info on rudder design http://www.philsfoils.com/designTips.html One interesting thing is that the rudder is generally made a little thicker than the dagger/centerboard. A thicker foil can be run at a higher angle of attack without stalling which is apparantly important with the rudder. I beleive the Idasailor rudder is Naca 0012 and also has a square tip. Dont know where you can find the Naca 0012 shape (maybe google "naca 0012"?) but this would probably be a good reference if your going to foil your own.
 
walt

walt

.
Jun 1, 2007
3,511
Macgregor 26S Hobie TI Ridgway Colorado
foil shape

This web site seems to have some good info on rudder design http://www.philsfoils.com/designTips.html One interesting thing is that the rudder is generally made a little thicker than the dagger/centerboard. A thicker foil can be run at a higher angle of attack without stalling which is apparantly important with the rudder. I beleive the Idasailor rudder is Naca 0012 and also has a square tip. Dont know where you can find the Naca 0012 shape (maybe google "naca 0012"?) but this would probably be a good reference if your going to foil your own.
 
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