Wind Vane Dimensions

[Chuck Valley]

Hey, folks

I'm down with Budget Boater for a couple weeks working on the Tiki 38. I have a set of wind vane plans, but they are back home. I am planning on taking some marine ply scraps back home with me to build it at home. Can someone send me some rough measurements ? I need the diameter of the ply disc at the base, rough width and length of the verticle supports and swing arms. It sure would save me space on the plane.

 

Chuck

 

[Axel]

Oops, sent the dimensions to Adrian by mistake.

Anyway, the base is 20(?) mm ply, 230 X 200 with a 150 mm X 9 mm ply disc on top of that. The sides for the lower unit are 300 x 70. The upper unit supports are 550 X 50. The blade is 1200 x 450 at the top, 230 at the bottom.

[Chuck Valley]

Thanks, Axel

That's all I need.

[Chuck Valley]

I just bought the plans from the Wharram website. Why reinvent the wheel? Here is a picture and drawing there:
http://wharram.com/buildingtips.html

[Dave Vinnicombe]

The wind vane system drawn by Hanneke is very good. Steers a T38 better than I can over a long period. Much to my relief. Its worth getting the plans as you point out - all the experimentation has been done. What is worthwhile considering is-
1. Make the vane from glass and 4mm foam. Its lighter and therefore the counterweight is lighter. This means there is less inertia and makes for better light wind performance.
2. Make sure all the blocks are light ball bearinged blocks. And that the control lines are thin dyneema, the stuff they use for kites is good. The lines leading into the vane assembly will need to be thick enough to be cleated. This reduces friction and again improves the systems performance.

Dave

[andy solywoda]

Although we have hydraulic steering, which would have to be disconnected to allow a windvane, it would be nice to have a self steerer that doesn't rely on electricity. Hanneke's design is very attractive, but our rudders would not allow trim tabs without a complicated installation. I downloaded a self steering book by Peter Forthmann that has lots of information about windvane steerers and his recommendation is for a servo pendulum system. He provides information such as wind and water vane areas, also linkage ratios, vane axis inclination, and range of motion. It looks like a pendulum steering paddle could be easily adapted to a tiller bar. A pair of stays port and starboard would provide a pivot and the paddle would act directly on the tiller bar. A stay from the lower portion of the paddle to the rear main beam would hold the paddle in the fore and aft position.
Another project to add to the list.

[Chuck Valley]

Wow! My eyes glazed over at "vane axis inclination". I don't want to design a hammer; I just want to drive a nail...........Good luck on yours. As I'm still in the building stage, we can make trim tabs, (lashed?????)

[andy solywoda]

The wind vane pivots on an axis that is set off the horizontal, and in the downloaded book that was set at 20 degrees. It looks like that's what Hanneke has in her drawing. Probably step down the windvane rotation to 1/2 at the trip tab.

[andy solywoda]

     My dock neighbor gave me his info on Walt Murray's DIY wind vane designs.  I was able to find this link to all that information, including design evolution, drawings:

http://www.mistervee.com/?q=content/walt-murrays-website