CoosBayLumber

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Pylon racer dihedral

I am trying to build a pylon racer off one sheet of two for a very old pylon racer. I got the big money sheet, but seem the notes are on the other sheet which happens to be missing. The aircraft was built in about 1962, and AMA knows about it, and has near zero information on it. There is zero information on the surviving sheet as to what was the original dihedral angle. The aircraft has about 575 S.I. on a 50 inch wingspan. Is powered by a .15 glow engine. It has strip ailerons, fixed gear, big fin but small rudder, and very sleek looking.


What dihedral angle or amount was popular back then and what is it today?
And please remeber, this thing has gotta turn hard and right-now.

Wm.

Flypaper 2

I still have one out in the garage hanging up, not quite finished and started to build in the mid 60s. It's a 40 size Rivets. I'm a slow biulder.. Has about 1 1/2 in. dihedral. I could measure more accurately if you like. As you say they didn't have much.

CoosBayLumber

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I have the plan for a 40 size Rivets by Jerry Nelson. However, it looks to be a copy of a copy and run through a blueprint machine too. Can figure out most of linework, but near zero of the text. It was put together for the then popular Goodyear events.

I am thinking this purpose built racer had near to 1 degree of dihedral, but doubtfull anything near two degrees.

Wm.

Flypaper 2

I'll measure it up just for hellery and let you know.
Okay. It's 47 in. span right on, and 1 3/8 under each tip. Had to do some finagling as the fuse belly piece is attached to the bottom of the wing. This is the low tail not the T tail. Hope this helps. Plans are long gone.

HighPlains

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I've got a couple of Jerry Nelson's original Formula One plans too. He designed 9 different airplanes for the then new pylon racing event. What most of the people that race today don't know is that he conceived of modern pylon racing and developed the inital concept and rules.

Prior to 1958, most RC flying was rather limited, since none of the receivers of the day were very selective. So most flying was one at a time unless you were on an amateur radio band. So pylon racing (AMA rules) was done against the clock, one at a time. Not much of an event to watch, 5 laps around a two pole course that added up to 1 mile. Even so with the engine to wing area limit, the times were slow, the winner of the Nats in 1958 averaged 35 mph.

In 1958, the FCC changed the rules to allow 5 more frequencies on the 27 MHz band. This then required the hetrodyned receiver (frequency mixing to a lower I.F. frequency). Fortunately, the transistor was making it into radio equipment, improving both costs and weight of the airborne equipment.

So in the early 60's the radio technology intersected with the desire to run multi-plane races, and Formula One was invented. Early races had some of the fast guys nearly breaking the two minute mark on the 2 1/2 mile course. But most were pushing almost 3 minutes. With .35 engines and 10-6 props, these early racers had wing loadings that approched that of a manhole covers due to the heavy radio equipment. An average radio of that time weighed between 1.5 to 2 lbs.

Tall Paul

That class of pylon racer is long gone.
The rules were 3 sq. ft. of wing for .09s, 4 sq.ft. of wing for .15s, and 5 sq. ft of wing for .19s.
The last time I competed, back in '64, deltas with .15s were cleaning up.

Flypaper 2

I still have my old Hustler Delta with a KB 20 DF engine with a tuned pipe. Still fly it once in a while. Flew with Ed Izzo and Hale debolt in Northern New York At, I think it was the Syracuse club at the Indian reservation. I flew in the novice class where you could fly anything you wanted. All for fun. I flew a homemade Ugly Stick with a homemade foam wing. Got disqualified for cutting the pylons. Still have on video tape from movie film almost getting run over with Hales racer when he got a little out of shape. Comes at you real fast looking through a camera lens. Sorry for the nostalgia trip.

CoosBayLumber

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Fly....

had talk with Jerry about two years ago. Showed him my plan too then. It was the low Hoz-stab, and his major mention was to look for the Tee tail design for it was better, but how?



I also heard same story about early Pylon days from Hal, but he remembered it coming in a bit later in date. The SuperHet radios being generally distributed beginning about 1960. I got a story from M.A.N. (circa 1963) by Nelson on how to devise new rules for the Goodyear events. I think they took off but peetered out by about 1966 for lack of participants. It then evolved to the system we see today. Nothing special, just fast.



But, now that it has been mentioned, just why were most the sucessful racer designs then based upon the Delta?



Wm.

HighPlains

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Actually Formula One lasted as an event for over 30 years, with the last event in 1998. It was special and very demanding to build and fly. Todays events are faster, yet lacking the beauty of F1 airplanes. All are much easier to operate with the low nitro engines and lighter wing loadings.

CoosBayLumber

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High....

Back up one sentence. Goodyear and the demand for near exact scale models is the reference. The Formulae are similar, but not the same.

There also was some interest into creating an ARF racer as I remember. It may have worked at t local level, but wasn't widespread. I oft' wondered what was then the accepted for an ARF racer.



Wm.

HighPlains

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Goodyear and Formula One was the same event. Over time, the rules evolved slightly, but the essence remained the same - .40 engine, 450 square inch wing, semi-scale model based upon the Goodyear/Formula One full sized aircraft designed for closed circuit racing starting in 1947. The width of the fuselage was only 2/3rdths the width of an actual scale model at 3 1/2". At the 2 5/8" scale, this would have only been 16" wide, where most full size airplanes are around 24".

The first model race was held in Turlock Ca. with about 20 entries. The populary of the event rose until the NMPRA had 600 members, but fell off as the speeds increased and winning times decreased below 1:20 to 1:30 range in the early 70's. By the 90's fast times were usually sub-teens, and often under the 1:10 mark.

The early years put more emphisis on scale like details, while the later years favored the shiny finish. Towards the end the airplanes were much more refined, engines were much more consistant and powerful, props more developed. But costs ran away - at the end a typical run cost around $7-8 for just fuel and a plug. Throw in the high engine mantainance costs, travel expenses, and time to build that type of model over and over to replace attrition, you are left with a small pool of contestants. That, plus an effort by some to fix the results of some races helped kill the event.

Flypaper 2

Sort of the old "how fast do you want to go, how much are you willing to pay" syndrome. Still have an article by Debolt on how to modify a wood prop into a racing toothpick prop. I think that's where the Nelson engines evolved from.

Tall Paul

The Hustler and the .15 deltas told me I wasn't cut out for flying really fast airplanes!
The upper left Hustler had a ST 46.. Used it for an FAI speed record trial at Dahlgren Va.. splattered all over the place..
The large one is the .15 sized with a Speed 600 motor... in 30 years they hadn't gotten any easier to fly..

HighPlains

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Your Hustler unzipped!