need help to build rudder blade, mac 22

[alfred gamil]

I would like to build a wood rudder blade for my Macgregor 22 ,( 1982 ) anybody can help me with the dimensions , the thickness of the old one is 1- 1/2 '' ( front edge ) to 1/4 '' ( back) and it is really hard to find a piece of wood of that thickness. actual length is 4 ' and width 10'' ....does the cross section have to be like a drop of water shape

Thanks

 

[ChockFullOnuts222]

You'll be able to steer the boat with a perfectly square-edged plank of wood, but it won't steer as well and will produce a lot more drag. The foil shape of the cross section does matter, but doesn't have to be perfect.

I did a drawing with measurements for someone last year, based off of the rudder blade from my '72 V2-22. I'll post it here later when I get home from work.

 

[Sumner]

Check the post down the page....

http://forums.macgregor.sailboatowners.com/showthread.php?t=126954

...for ideas. It needs to be an airfoil shape to work well. Idasailor..

http://www.idasailor.com/catalog/default.php

....probably has them also. Not cheap, but extremely good. We have one and love it. Also it would work right the first time,

Sum

Our Trips to Utah, Idaho, Canada, Florida

Our MacGregor S Pages

Mac-Venture Links

 

[justsomeguy]

I would like to build a wood rudder blade for my Macgregor 22 ,( 1982 ) anybody can help me with the dimensions , the thickness of the old one is 1- 1/2 '' ( front edge ) to 1/4 '' ( back) and it is really hard to find a piece of wood of that thickness. actual length is 4 ' and width 10'' ....does the cross section have to be like a drop of water shape

Thanks

If there's a real lumber yard near you, you could ask the folks there for "eight-quarter" stock ( O, Canada, I wonder what the metric equivalent would be?). It will be two inches thick. Then, there's always laminating two 3/4 + boards. I'd use a polyurethane glue like Gorrila glue. Hey, I used to drive South into Canada for beer!

 

[timebandit]

I really like this way to build a wood rudder.

Start by gluing 2 pieces of 3/4 inch plywood to get your thickness.

I would use glue and some dowels.

Then have at it with a belt sander and very agressive paper for shaping.

Then cover it with fiber glass I don't know if I would use the stripes.

 

[ChockFullOnuts222]

As promised....not quite to scale, but the measurements are correct as taken from my existing rudder....

 

[alfred gamil]

Thanks for the advise, I finally found a nice peice of mahogany with the exact dimensions, I will try it this way, but do I really need fiberglass, dont you think 5 layers of marine varnish will do, since I dont leave the rudder blade in the water when I dont use it

 

[alfred gamil]

Thanks for evrything, so nice of you to do this work,
I am surprised that the blade is flat on both sides ,my old one is really curved like a plane wing.?????????

 

[alfred gamil]

Thanks for your reply, how does canadian beer taste for you?I am not a beer amateur except for Tcheque and german beer, I like wine .
I started working on the rudder..

 

[alfred gamil]

I forgot to ask you about the best way to work to be able to get this curved shape ( plane wing...foil..like the my old one...) the actual maximum thickness is 1-1/2 ''..

 

[alfred gamil]

Thanks for your reply....
ida is 600 doll,really expensive...i prefer to put this kind of money on sails.....I have genoa, small genoa, jib, storm sail, spi and some need to be refreshed..thanks...

 

[timebandit]

If you use solid wood you will be ok.

Thanks for the advise, I finally found a nice peice of mahogany with the exact dimensions, I will try it this way, but do I really need fiberglass, dont you think 5 layers of marine varnish will do, since I dont leave the rudder blade in the water when I dont use it

 

[alfred gamil]

do you know the thickness of the ida rudder blade for mac 22 , 1982 ?

according to naca 1 inch is the thickness, going along with the 10 inches width

 

[Mac]

After reading Sumners modifications and thanks to Dan Nease, who I could not have done this without Dan, I have started making my own rudder. I'm using 3/4 maple plywood glued up. I will include more pics as I go. The first four pics are of my old stock rudder. ShareThis

Attached Thumbnails

 

[Mac]

I will try and post the pictures of my new rudder. Maybe someone can help me. It is under the title "Pictures of my new rudder" in "Ask a Macgregor owner"

 

[timebandit]

My Ida blade is 12 inches wide with a thickness of 1.4 inches.

do you know the thickness of the ida rudder blade for mac 22 , 1982 ?

according to naca 1 inch is the thickness, going along with the 10 inches width

 

[justsomeguy]

Thanks for your reply, how does canadian beer taste for you?I am not a beer amateur except for Tcheque and german beer, I like wine .
I started working on the rudder..

I'm not a beer amateur, either! Canadian beer, at the time, was much better than the swill available where I was living (Southern Michigan). Good luck with the project.

 

[Phyrexii]

My boat didn't come with a kick up rudder, and I didn't want to sail without one, so I made a quick and dirty (and cheap) one from a 2 x 12, with a couple of oak cheak plates. I ran the lower blade of the rudder thru the table saw set to 15*, to make both a leading and trailing edge. While this shape is not a true hydrofoil, it is still better than a flat (blunt) front edge.

The biggest problem with using solid wood is that it is boyant. This rudder has aproximately 12 pounds of boyancy, so I had to make a counterweight that goes on the end.

 

[Timo42]

I went with the Idasailor rudder, bigger improvement than new sails, but this article from West Systems on rudder and daggerboard construction has a lot of information. When I build my I550, this is what I will do.