As usual, the (re)designers have been at it! Here are some of the Whipper Whiz hop-ups that people have done to improve performance for the competitions.
From Tom Broesky tjb "at" adesigner.com (Dec 22, 2000):
Here's the record plane. http://adesigner.com/whip.htm. The elevator is slightly back to allow trim. Makes all the difference in the world. The thermal that blew through helped a lot too. We will see how the indoor contest goes.
Now that Harley has taken off any requirements other than the 1" x 6" wing, we should see some interesting fuse designs.
From John O'Sullivan spinifex "at" attcanada.ca (Dec 22, 2000):
The biggest improvement I have found, is in using a longer fuselage and smaller tail and with both wing and tail set at 0 deg incidence. This allows the CG to be moved back to 50% wing chord and prevents "loopiness" during launch, while still giving a good stable pullout at the top. I have weighed 10 of my remaining models from 17 built (others were given to spectating kids in an effort to corrupt them into flying). Weights of the standard Whipperwhiz range from 2.1 to 2.8 grams, with most coming out at 2.2-2.4. The exception to this is # 9 which I ballasted to 5.1 gm and was used to set the 131 ft distance flight. In the spirit of the contest, no attempt was made to use special lightweight contest balsa
I modified three models with a longer fuselage - 5.75" long, with wing back 1.5" from the nose (1/8"X1/4" balsa tapered to 1/8" sq.). Tailplane and fin 1/32 balsa. Tail 7/16" chord, 1 5/8" span with somewhat elliptical taper. Fin 1/2" base, 5/16" tip, 5/8" high. One of these has a standard wing (#10a), the second has rounded tips (#16), and the third (#17) has swept back LE elliptical tips. the weights of these are 1.8 gm for the standard wing model and 1.3 gm each for the other two. The wings were thinned towards the tip to about a little bit less than 1/32". My best time of 11.82 was done with #17. This was without thermal assistance. The amount of time I have spent flying these models has been minimal, and I have no doubt that these times can be improved on by a wide margin. Occasionally someone is going to get a thermal and push the time to a minute or more, but the fun is in getting the little thing to achieve a good still air time. Indoor flying would be a good test of this.
As Harley said, the secret of performance is not so much in the modification of the design, as in the launch attitude and angle.
-- John O'Sullivan Nova Scotia
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