Dimensions For Parts

S

Starfish

New Member
Just curious......does anyone have the full dimensions for the new style rudder and center board for the SF???

I would like to draw these to full scale in AutoCAD to use as templates to make a set for myself. I am currently using the old style blades and would like to upgrade someday. And no - I will not be racing.

Any help here is appreciated.
 
I purchased a very nice rudder blade from our member Adirondaker.

Look in the posts for a posting titled PARTS FOR SALE (MOSTLY OLDER). He produced several rudder blanks from mahogany stock for a camp he helps direct. I would contact him if he has made a second batch of which he would have the dimensions and techniques at hand.
 
Thanks for the tip...........I'll see if I can contact him. I ran across some dimensioning in the ISCA Class Rules but they are not complete by any means.
 
Adirondaker was kind enough to respond to my inquiry but he is using a pattern. So........I'm still looking for dimensions if anyone can help here.
 
Hey Starfish,
I have made a few sets of rudders, tillers, and boards. I am friendly with the guys at the local marina, who also happen to be sunfish dealers. I traced the shapes of the parts, and made templates, including where all the holes and fittings go. Other than that, I use the measurements from the ISCA, and make nice straight, sharp trailing edges, and more rounded leading edges. I draw a centerline around the cut out blank, and use planes, a spokeshave, and sanders, slowly shaping the piece. You just have to get a feel for what you are doing. I don't know how that would work on a CAD though. Try to find a sunfish dealer near you, maybe they'll let you take measurements from parts- maybe not. Or, if you know someone nearby with a rudder and board, maybe you can take measurements off of them. Trace the basic shape, and use a homemade profile gauge to figure out the different profiles on the pieces. You can make one out of a scrap of wood and some bamboo cooking skewers.
 
nikobrogna -
Thanks for your response. You are fortunate to have the SF parts to make your tracings with. Unfortunately there is not a SF dealer anywhere near my location and I do not know anyone that has a SF..........:(

AutoCAD is a great tool and is the perfect way of making precise templates for just about anything imaginable.....if you have the dimensioning of parts. So far, I have been able to draw up the daggerboard from the dimensions shown on the ISCA Class Rules....which is a start. Although the "foil" profile of the rib shape is not given on those particular pages, I have decided on a modified NACA0012 foil profile that should work fine on the daggerboard. It is a symmetrical foil and should work very well. Since I design and build model aircraft, the shaping aspect is nothing new......it will just take a little more time due to the wood being more dense than the balsa that I normally work with building the wings for my planes. But the concept is the same......:)

I'm thinking that there may be enough dimensions shown on the ISCA Class Rules for the rudder to at least get me close. I'll just use the rudder that I have for those dimensions not given where the tiller attaches. I should be able to get things reasonably close here between the two resources. I plan to just use the same foil shape on the rudder as that on the daggerboard.

The one thing that I'm unsure of - and maybe someone can tell me - is on the daggerboard: does the foil shape "taper" down in overall thickness as you go towards the bottom end (length wise) of the board? In other words, is the thickness constant? In dealing with wings....it can be constant or it can taper from the root chord to the tip chord. I can do it either way but I would like to keep the shape similar to the stock piece.

Again - thanks to everyone for their help!
 
Starfish, I am an architect when I am on terra firma. I have access to AutoCad, 3D Studio Viz, SketchUp, Revit,..........you get the picture. I still have my original rudder blade that came with my 1979 SF. I have used it and a newer blade made by Adirondaker. I could "trace" the plan of the '79 blade and transfer it to AutoCad for you. I have taken photos of my newer blade as I have doweled it for threaded S.S. rods. Either way I coud send you a .dwg file and some photos if you would like.

Nikobrogna has the technique down to shaping. I would have to say looking at a finished blade, and feeling (taking profile measurements) the tapers would be easiler, but photos can help too.

Have you contacted Al Courtines (Al Court)? He is a member here too and best of all a wood shop teacher to boot.

John Howard a.k.a. SuperCub is an avid model airplane builder too and sailor here. He uses computer aided design for both sports. He also has a great inventory of "how-to" info for many projects.
 
Repeat –
Thanks for your offer! Although I hate asking you to do all that work as it could be very time consuming unless you have a large format scanner at your disposal to scan the tracings. The blades that I am currently using are the original design as shown on page 7 of the IRCA Class Rules at this URL:
http://www.sunfishclass.org/admin/ISCA_Regs/isca_class_rules03012003.htm

If you have the new parts and could trace them that would be great. If nothing else, I would be willing to pay the postage if you wanted to mail them……? Or a *.dwg or *.dxf file would be good too as well as a photo or two. I really appreciate your offer as this would be great!

This is not a “do or die” situation for me as my current parts are in very good shape and I have spent a little time this winter refinishing them. I just thought it would be nice to upgrade to the newer parts at some point. I have found a reasonable source for the blank mahogany wood so doing this myself is just one of those projects that I would like to tackle.

I have not had a chance to communicate with Al or John and only recall reading some of their posts here on the forum. I’m sure that both are on top of their game and have valuable input. I have been involved with RC aircraft for the last five years and have designed and built tons of planes…….and plane parts. No….I’m not an expert but I have really enjoyed learning this aspect of the hobby and find that building is just as much fun as flying……..maybe even more fun.

Sailing is my newest “obsession” and I’m in the infant stages of this particular hobby. I’m finding that there are allot of really nice folks involved in sailing just as there is in modeling. The only problem is that most of the clubs or folks involved in sailing are not located near my neck of the woods so it’s rather difficult to be involved in a “group” situation. Not impossible…….just not convenient.

Anyway, thank you for assistance with the parts thing. It is definitely appreciated! If you need to contact me just shoot me an email via my profile here and I will gladly respond. :)
 
I just wanted to say a big "thank you" to Peter for supplying me with the information that I requested. You've certainly gone way beyond the call of duty. Your effort and kindness are indeed appreciated!

:D
 
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