Septal III (oz9581)
About this Plan
Septal III - Double Header - Radio control contest model for rudder only. Plan shows 2 complete models at different sizes, for either .15 or 1/4-A power. Wingspans are 50in and 30in.
Quote: "Almost three years have passed since the first .15 Septal left the drawing board and work bench. From that time to the present, so many changes have been made on the ship, only three things remain the same as the original - the shoulder wing configuration, the pulse system and the name. Although the first one flew fairly well after being trimmed out, I wasn't at all pleased with its stunting ability. It was somewhat larger and heavier than the final version, and with a .15 up front, it just didn't have the steam I was looking for. Actually, it was more like an advanced trainer, although I could probably have boosted its performance by switching to a .19. I knew if I increased the power I would be defeating my purpose, for the popular .15 size engine was what I wished to retain.
The next version started to take on the appearance, if only in physical shape, of the final Septal III. Reducing the over-all size and shortening the nose moment arm, increased performance immensely. Changes in construction methods reduced the total weight, and the Fox .15 really moved the bird out. Maneuvers started tightening up, and over-all I could see a marked improvement. In some respects however, it still didn't qualify for the goal I had set for my dream ship. After many hours of flying and many CCG and decalage changes, I could see the Septal III much nearer. A broken B+ lead in flight ended any further testing on this version, but the information I received was all I needed to freeze the design. Many planes of the Septal II type were built and flown, and the Septal III, as it is now, was finally born. I realize now all the time and efforts spent were not without reward, as the Septal III has either won or placed in every meet entered. I would like to point out now that the .15 is strictly not a beginner's ship, but a high performing contest threat, capable of every rudder-only maneouvre, including true spins. Motor control is not just desirable, it is a necessity..."
Septal III, MAN, July 1962.
Direct submission to Outerzone.
Supplementary file notes
Article pages, thanks to RFJ.
Article pages (same, but OCR) thanks to rchopper56.
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User commentsI built the .15 size Septal in the spring of '63. Learned to do all of the stunts that a single channel could do with this plane and to date it is still my favorite. Used a home made pulse actuator from a micro mo motor with bang bang throttle control. Dad built the smaller one several years later but it could not perform like the .15 size.
rchopper56 - 22/12/2017
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