> My uses are loaded sea touring and sailing with Klepper jib and occasionally > a > S4 mainsail (without gear). > > One thought is to upgrade the blade to a Balogh style "balanced blade" design > as indicated in Ralph Diaz's Folding Kayaker book. /skip/ > How does a wider profile blade Balogh style perform vs a narrower and deeper > Feathercraft K 2 rudder blade profile. I have already deleted recent post by Tony Niilus, then some second thoughts have surfaced :-); since I don't have a Klepper, but do have a Folbot and Feathercraft rudders :-), here are some thoughts. Ordering a Folbot rudder for $135 and shipping it to Australia won't be too cheap. May be, to order blade only. Folbot blade is an aluminum sheet 1/8" thick (looks like anodized, but this isn't a big deal), and its shape is doesn't look good from the sailing point of view - wide and not balanced. You might have to re-drill and rotate it to make it balanced (Tony did that http://www.geocities.com/niilus/ ); though, such blade can be cut in any aluminum shop or at home for very liitle cost, and could be made not that wide, and balanced too. On the http://www.folbot.com photo shows Folbot old blade, no longer in stock. New one is larger, and can be seen at Tony's website along with Feathercraft rudders, so it's easy to compare. Wetted area of F-craft K2 blade is about 0.04-0.05 sq.m, which is a minimum (1.5%) for 3 sq.m. sail installed fore of the hull Center of Lateral Resistance (I think, 1.5% blade area is a formula for a sheet aluminum, not foiled blade). Foiled F-craft blade provides some additional lift, but it is a thin foil (3/16" or 4 mm), so this effect can't be significant. I don't remember total area of S4 rig - must be more than 3 sq.m. Wetted area of the new Folbot rudder is about 0.8 sq.m, adequate for a larger sail, but I think it can be made with a little bit smaller area (due to decreased width). Mark Longhaul sells his balanced blade separately (USD 100?). I didn't know it was calculated by Mark Balogh; No doubt, he calculated it well for Klepper, but again, blade with higher length/width ratio should perform better under sails - may be narrow aluminum plate wasn't feasible with such large area - it would bend more easily. *************************************************************************** PaddleWise Paddling Mailing List - Any opinions or suggestions expressed here are solely those of the writer(s). You must assume the entire responsibility for reliance upon them. All postings copyright the author. Submissions: PaddleWise_at_PaddleWise.net Subscriptions: PaddleWise-request_at_PaddleWise.net Website: http://www.paddlewise.net/ ***************************************************************************Received on Tue Apr 27 2004 - 16:15:20 PDT
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