Grabber (oz15314)

About this Plan

Grabber. Wakefield competition rubber model.

Quote: "Grabber, by Roger Simpson. The Roger half of the USAF's famous Simpson twins produced another contest winner with this Wakefield job.

Some people have the idea that modelers in California fly in ideal warm calm air with no down drafts. Nothing can be further from the truth, especially up here around Sacramento. The Grabber won four of the five Northern California Free Flight Council contests last year, and the first three wins took place in contests plagued by 15-25 mph winds. The model maxed out in two of these contests and dropped only four seconds in the third.

At the Dallas Nats last summer, I had dropped only one second going into the 5th round. Due to a broken stab suffered during a Navy rescue from one of the lakes, I had to use the stab from my number two ship which had already blown a motor. The stab didn't work too well and I didn't pick real good air; this added up to a 1 minute 57 seconds flight for a total of 13 minutes and 56 seconds, and I placed 6th. I had blown up my Unlimited Rubber model at the Air Force Championships so I flew the Grabber in Unlimited Rubber for team points, still with the number two ship stab, and again placed 6th.

The model was tagged with the name Grabber when another modeler noted that it seemed to 'grab' a lot of altitude in weather that seemed to hold other models down. This model is the third in a series of Wakefield designs I had developed in search of an easily constructed, yet consistent performing model in all types of weather.

The design prior to this one had a lower aspect ratio wing and a lower pitch prop. I went to a higher aspect wing and increased the tail moment arm hoping to increase the gliding performance. I'm satisfied that this has been accomplished.

The wing airfoil used in these designs is the same one Bob Hatschek had on his Skyscraper, only difference is that I use turbulator spars instead of a thread turbulator, as I believe they serve a similar purpose and make for more rigid wing construction. The stab airfoil is by Hank Coles.

The prop pitch was increased from 22 to 24 in, in search of a faster climb while staying with a fourteen strand motor. With the higher pitch prop, performance in the climb was improved, especially during the cruise part.

Construction: Wing: Make sure you use spruce for the spars as called for on the plans. Lightweight, straight grain balsa, should be used throughout the wing. Cover with Jap tissue and give it six or seven coats of dope. All finished it should weigh 1-1/4 ounces... "

Direct submission to Outerzone.

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