The design parameters come from WINDPILOT: selfsteering under sail
and Yacht Surveyor, Yacht survey, Boat survey, steel and aluminium yacht surveys
. The first link has a very informative book free to download, and the second link a paper that covers all the basics of windvane steering
geometry. The original idea for cable steering
was pilfered from the Autohelm
manual, available online from Scanmar. Windvane
construction relies on a number of hard and fast rules, eg the relationship between rudder
and trimtab, trimtab and vane, angles of inclination and geometry (explained in the downloads). It does not really matter how you wrap up the package so long as the basic parameters are adhered to, and your construction eliminates friction and inertia from the system as much as possible. In my case, the final design was dictated by the materials that I had available and what I was allowed to salvage
from the non-ferrous scrap bin at our local engineering works.
Attached a pic of the cable attachments on my gear
. Bicycle gear cables
have a little ball on one end. The cables
thread through the 'U' shaped bits, secured by the ball and then down thru the two tubes. Shimano make high end derallieur cables and sheaths from stainless and teflon that are friction free. Your bike shop will have them.
If you are about to embark on the construction of your own gear then be warned - it is a very addictive activity!!