Demon (oz2785)

About this Plan

Demon. Nationals Winner. Free flight gas model from MAN 1941.

It is safe to say this design was greatly influenced by the classic 1939 Carl Goldberg Zipper (oz387) design.

Quote: "A Record Holding Nationals Winner. Build and Win Contests With This Plane That Made a National Three-Flight Average Class B Senior Record of 9 min 20.3 sec at the 1940 National Meet. Demon, by Bill Redecker.

WING DESIGN BY COURTESY COMET MODEL AIRPLANE CO.

WITH a defiant scream and a challenge to the clouds, a mighty little ship leaves the hands of its builder - up, up, up into the blue, climbing higher and higher with a tight vertical that commands the admiration and respect of every model builder on the field. Fainter and fainter grows the high-pitched roar of the motor as the little ship is rocketed skyward. Then, as the twenty-second mark is reached, it flips out on top, begins a long, flat glide, soars majestically while spectators gasp as another first-place is hung up with its line of victories.

It's the Demon, fellas, the little ship that can't be beat! It's made a flight of 28 min on a 10-sec engine run.

The plans call for the installation of an Ohlsson 23, but the Demon may easily be converted to a class C ship by using a Baby Cyclone. In taking advantage of the adaptability of this fine performer as a dual class ship, the builder should take care in conforming to the weight rule. The wing area is 3.29 sq ft (474 sq in) and with an Ohlsson the ship must weigh at least 26.5 ounces to have an even 8 oz wing loading. The use of a Baby Cyclone calls for 28.8 oz as its minimum weight. This yields an 8.75 oz wing loading.

Due to the chance of losing a ship in a contest, this plane was primarily designed for simplified construction without sacrificing its performance. If you lose your ship one week you should have easily completed and thoroughly tested another potential winner by the time the next week rolls around.

The Wing. The wing is of the elliptical type with polyhedral built-in to insure complete stability under extreme power. Its construction is light yet stressed to 'take it' under the roughest treatment in flight or in contact with obstacles.

Enlarge the plans upon a suitable piece of paper and tack them to a board or work table. Cut the trailing edge from medium 1/8 sheet and put in place upon the plans. Then, using light pins and nails, bend the leading edge to its shape. Cut the ribs from 1/16 sheet and put the ribs in the tip section, slide the tip spars into place and use the same procedure for the center sections. When the four sep-arate sections are dry, glue them together at the polyhedral joints. Covering is of 'Silkspan' or bamboo paper. Two coats of thinned-out dope are suggested. Sanding with fine finishing sandpaper will give a smooth surface.

The Tail Assembly. The stabilizer is constructed by cutting out the leading and trailing edges and tack-ing them in place upon the board. Then cut the tapered spar and slide the ribs onto it and glue the entire structure as you place the ribs and spar inside the leading and trailing edges. Using 3/32 square balsa, glue in the diagonal braces which run from the spar to the trailing edge. Then plank the center section with 1/16 sheet on top and bottom as the plans show..."

Update 24/08/2018: Replaced this plan with a clearer version, scanned from a full size drawing, thanks to JJ.

Quote: "1940 Nationals Winner. The Demon. Class B and C gas model, designed by Bill Redecker. Traced from drawings by Bruce Chandler and the original 1939 Conet Zipper plans, see March 1941 Model Airplane News. Bill Thompson 8-21-65."

Direct submission to Outerzone.

Supplementary file notes

Article, MAN 1941 (includes full wing rib templates).
Previous scan version.

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