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: Wing Wobble
- Re: Torsional Strength