Date: 10/22/1998, 7:28 pm
Thanks again in advance to all you fonts of knowledge. Since my kayak now had a �wing� rudder, an indefinable sense of logic, symmetry, and aesthetics dictated that I paddle with a �wing� as well.
Since no one seemed to think there was an optimum wing curvature for a paddle, I used the illustrated cross section I found on the WEB. ( http://www.paddles.com/library/basics9.html). Since it was to be a Wing paddle, for purely aesthetic reasons, I took a chance, and designed the silhouette more like a natural bird wing. Borrowing from the R/C plane modelers, I built the forms using wing struts similar to �stripper� stations. Both forms were �stripped� with 1/32� x 1� balsa and glassed.
Assured that the blades would be sufficiently stiff, I laid up the wing paddle using Epoxy and two layers of 5.7 oz. graphite cloth with a 2mm core of Fiberllay�s �CoreMat�. The blades weighed 4.4 oz. &4.5 oz. Epoxied to a 14 oz. hollow cored, resin coated wood shaft, the paddle weighs 27oz. (including reinforced throat and a sleeve for two piece break apart.)
So... It twists. Lengthwise, it is stiff enough to resist bending when I exert maximum effort holding the tip and throat. (A bit softer today, but was a blocking tight end at San Jose State.) Trying to spread the blade at its widest produces no discernible effect. But... with one hand, I can easily twist the blade tip (prox 10+ degrees ) Not being a materials expert, this would not surprise me, except the pictures I�ve seen of wing paddles appear to have no dihedral or any other manner of reinforcement.
Once again, I�m at an impasse. I laid three strips of two inch fiberglass widthwise on the concave surface, and only added a few ounces, but resistance to twisting. There�s usually some esoteric (obvious to some of you) mechanism at work when I play at designing these things. Can anyone help?
Thanks, Tom

Messages In This Thread
- Wing Wobble
Tom Scheibe -- 10/22/1998, 7:28 pm- Re: Torsional Strength
Mark Kanzler -- 10/27/1998, 7:54 am - Re: Wing Wobble
John Lange -- 10/22/1998, 8:48 pm
- Re: Torsional Strength