October 1962 American ModelerTable of Contents
Aeromodeling has seen significant changes over the decades both in technology and preferences. Magazines like American Aircraft Modeler, American Modeler, and Air Trails were the best venues for capturing snapshots of the status quo of the day. All copyrights are hereby acknowledged.
This installment of Bill Netzeband's "Control Line Capers" column in a 1962 edition of American Modeler magazine is the earliest instance I remember discussing what relationship - if any- the location of the bellcrank in the fuselage has with the models center of gravity (CG). As it turns out, and elementary physics would suggest it, the determining factor it the location of the leadout line guides on the wingtip that is important to flight characteristics. The wingtip leadout guides act only as a pair of simple pulleys to change the direction of the applied force, so once the line are past the guides, it does not matter to the airplane where the pulley is located (assuming a rigid airframe).
Wild Bill Netzeband's Control Line Capers
This time ... True Confessions, Relativity, Models and The Works. [Pretty happy about our second contest attempt in many years: 3 firsts out of 3 (Stunt, RR & NC)! One of those days when you just can't do anything wrong - to make up for lots of the other kind. Wichita, Kans., July 1. Yes, there were other contestants.]
Misconception Blasted. Pictures illustrate that the bellcrank has no effect on locating the CG. Rather, the bellcrank should be on the CG to prevent binding (Pic #2). CG will always fall in line with center of line lead-out spacing (1, 2 & 3) during flight. Locate your lead-outs relative to the CG to produce desired yaw angle for proper tug. We have settled, experimentally, on a 6 degree rake. Proof later. Next time a guy tells you to locate your CG forward of the BC or in front of the lead out, shun him. He don't know the facts. The CG comes first, all else is related to it.
Scale Or Semi-Scale Stunt. Frank Beatty, 862 N. 73rd St., East St. Louis, Ill., in his Scale Column in "The Bulletin" suggests cataloging model magazine data with index cards, cross-filed by event, type, feature. Wish we'd started doing this a long time ago. Hez also advocating Scale Stunt. If Frank and Charles Parrott (Semi-Scale Stunt Team) will get together we might have the makings of a new event.
Information Please? Two methods exist to gain information ... research it yourself or accept some other's data. I used to try the first method, but found it impossible to cover the field. So we ask questions, and rely on (steal?) other folks' combined knowledge. The manner of questioning is important. Rather than "Man, you really stacked that in. KA-POW! Whajado? Lose it?" - try "Excuse me, did they add a stem to that maneuver?" Be polite but firm and clear. Also practice ducking fast ... very handy maneuver sometimes.
How Fast Is Fast? To define or describe, we reach into our experience and relate the action to similar actions we have witnessed. You read our description. The words trigger your memory and you relate as we did (but with your own experience). Right now we're close to trouble. I said the ship was "quick" based on 14 years of flying everything, but you have flown only trainers and nose-heavy equipment. Didn't get together, did we?
Some day, sport fans, we'll describe it thusly, "The test model using Brand X Flight Recorder (Ser 0071), configuration D3 in accordance with test procedure Par 6.3 thru 6.14 - Model Aircraft Standards Manuel - performed as follows:
Level flight speed, 106-mph. Time to reach maximum angle of attack after application of 30 degrees elevator, 10 millisec. Time to complete 90° turn, 0.1 sec. Average turn rate, 900 degrees/sec. Minimum turn radius, 10.2 feet. Model placed in Category C4 for reaction to control command."
Whenever an absolute measurement can be made to compare with a standard, no argument exists. Opinions always trigger discussion. Presently all we possess is the stop watch, later we hope for better test equipment. Until then we'll try to qualify our observations clearly and hope to reach most of you as accurately as possible. A sage once said, "The' best way to avoid mistakes is to do nothing".
Mid-America Stunt Championship. Sept. 2 at Lexington, Ky. Lew McFarland (1961 Grand Nats Stunt Champ) judging, with trophies to 5th place, some cash and a High Point Trophy. Also Scale Stunt and as many flights as you can make. With John Peck and Lew officiating it should be a grand day for all.
Sirotkin Stunter from Europe. The model while following "classic" American lines is different in spots. Wing area totals 620 with flaps, nose to tail moment arms 1:1.5, CG at 17% root chord, stab-elev area 113-sq-in (18.3% wing), large fin area, low ground angle - all these fit our present standard. Difference is in homebuilt hardware: "X"-shaped bellcrank, one side for flaps, other for elevator, spinner, control horns. Uses a .29 "Komet" engine (like Russian combat types) on pen bladder tank swinging a 9-7/16 x 4 prop.
Construction is sound and simple utilizing block-and-slab fuse with "I" beam spar assembled "Detroiter"-style thru the fuse. Planking, cap strips and the works indicate long life. Finally the airfoil is 20-21% thick, reflexed curve style.
Miscellany. (1) During an average day of Rat Racing, the good pilots travel (trot, run) 1.7 miles, if the ship runs 50 laps per tank. The pit crew travels a total of 30' (3 pit stops) consisting of 5 feet after catching the ship and 5 feet back to launch (if they move at all). Of course, the pit crew can also travel several miles if the pilot ain't sharp.
(2) Help - Anyone got details (facts, figures, views) of the German Gotha Bomber, the Breman, the Martin B-10, or the Barling 2 1/2 Wing Bomber? Contact Eddie Albers, 458 Pilgrim, San Antonio 13, Tex.
(3) Did you ever notice? A contest official thinks a contest is a full day of frantic activity with no time for anything, while a contestant thinks a contest is a day of boredom punctuated by short periods of furious activity. Unless you are the Meriwether's or Woody Blanchard.
(4) Flite Co., 6109 Pondarosa, NE, Albuquerque, New Mexico, has a retractable landing gear set. Operation in 6-sec by servo power, weight 2.2-oz, supports 9 1/2-lb R/C ship utilizing torsion rod mounting. $29.95.
(5) Stanton Hobby Shop, 4734 N. Milwaukee Ave., Chicago 30, Ill. (KI-58185) has an unusual line of used engines, old and modern. If you need Perky parts, an $8.00 ST Jubilee, Copper King parts or a Rogers .29 or Drone Diesel (new in the box $14.95) write to them. They buy-sell and trade with a good line. Better just send for their catalog.
Plastic Props. Finally figured how plastics get more efficient than wood, in spite of their greater weight. Simple, really. The blades are accurately pitched right down to the hub, hence more blade efficiency. The plastic materials are now stiffer and advanced techniques give better molding. You realize that if a blade is under pitch angle at the root it operates at a negative angle, thus detracting from thrust in the air. And they are still practically unbreakable.
Requisite for Ideal RR Pilot. (A) Arm from top of head (only one required) with strong oversize muscle for whipping. (B) Left leg shorter than right leg to impart natural leaning stance. (C) Large, flat feet with tough toes. (D) Variable height from 2 feet to 7 feet for ducking and reaching. (E) At least one hump (a la camel) since it gets awfully dry out there.
Next Month-The Ideal Stunt Pilot.
Femme Fatale. Accidentally discovered an incentive for beginners. Bob has resisted CL, while building FF models for several years. At the Ponca City contest he witnessed two 10 year old girls flying in the Novice Ukie event. That did it! He picked up the handle and has been flying heavily since. So, to interest your sub-teen boys, first interest a sub-teen girl. Fool-proof? We don't know, for sure.
True Confessions All Round. After welcoming "Battling Bob" Hatschek aboard, we'd better clarify our own black marks! I built solid models, flew FF glider, rubber and gas, had two radio ships (and precious little control), flew indoor models, outdoor ornithopters and auto-giros, ran boats, chased girls (oops) and then settled on CL. Like Bob and I've been contending "We're all one big hobby family".
Toy Airplanes? Letter from a lad who will remain anonymous asks how to convince parents that models are not a waste of money and time. First we must wipe out the "toy" stigma, by education and demonstration of a model's complex nature and worthwhile benefits. A trip to a good contest might help. Here our work can be seen first-hand and at its best. Pointing out all of the modelers who are now famous, successful grown-ups could help. Understand John Glenn was a modeler. Basically the education and advertising afford the best avenues for success, but we must present a good picture through media outside of our own model mags. A tough assignment, but possible.
A Told Tale - Now son. let's watch this fellow's pre-flight procedure. Notice that he is running his lines out with a clean rag and talcum powder. They pick up oil and dirt and would stick without frequent cleaning.
Over in the pits, he had the cowl off checking engine bolts, head bolts, glo plug, tightened the prop and spinner, examined his controls for binding. While he was there he looked over his fuel lines for leaks and cracks.
He's checking his controls now. Notice his helper signaling up, down and neutral. Seems OK so he checks that his clips are closed. He'll fuel up now. See, after his fuel overflows, he blocks the overflow vent and gives it another squeeze. That'll fill the line up to the needle valve. Now a light prime of fuel in the exhaust and hook up the plug wires. No, he isn't kissing it, he's blowing into the exhaust to vaporize the fuel. Guess he flooded his plug.
Now notice the signal to the judges and watch that propping hand. A good hard flip and she's purring. He'll leave the plug wires hooked up for about 10 seconds while the engine gets warm, and then he'll listen for a few seconds after disconnecting to be sure it stays hot, and that it's set right.
There he goes out for the handle. Seems calm doesn't he, like he's done it before. See how he checks around the circle to make sure it's clear. Now the hand signal for release. Notice how smoothly it rolls out with neutral control.
An easy climb to 5 feet and - oops.
Why did it land so soon? Guess he grabbed the handle upside down. Oh well, let's go over and watch Combat.
FAI TR Bodies Ready. Bob Watts, Liberty, Mo., has cast fiberglass, red, white and blue FAI TR fuselages and matching cast alum pan. Write him for info. We're building around one now.
Down By The Old Mill (Cha·Cha·Cha). (1) To gain one MPH with a given prop you must gain the following additional RPM: 4"-264; 5"-210: 6"-175; 7"-150; 8"-132"; 9"-117; 10"-105; 11"-96; 12"-88. All this assumes the same prop and airplane combo. Gets tough later.
2) Fast Fill for Rat and Team Racers available. John Barr got his rubber filler attachment manufactured. Fits into a 1/2" OD tube and enables a one-plunge fill for pressure tanks. Construction similar to a duck call (so we tried it and attracted one irate blue jay). Word of warning. Operate clean, since a hunk of sand or gravel could hold the lips open and lose your seal. Device is not limited to pressure tanks - we're also using it in a non-pressured quick-fill system. Very good item, well worth the 50c tab.
3) Supertigre G. 21/35 was given the acid test in competition. After 1/2 hour on bench, slipped into the "Goofer" RR for flight break-in. Started runs at 85-mph on rich side with 12% Nitro and 29% oil fuel on 8 x 8 Tornado Nylon prop. The engine was so reliable about hot starting and so steady in the air we decided to use it at Wichita. During two weeks we flew about 20 miles a nite with L. H. Hoff doing the honors in the pit. At contest time we had about 2 1/2 hours (not broken-in by ST's standards) but the consistent 94-mph speed sounded good enough. It was. In short, during 70 lap qualifying our time of 4:03 was high, and our winning 140 lap time of 7:36 was 1:30 better than second. (Not 6:13 by any means, but 79-mph avg with LeMans start ain't hay.) The engine obviously has more in it since with MM fuel and Johnson plug it still runs on the cold side. The other 1/2 hour will help, and with 100-mph speed and pit stops with fast fill, should knock off some time. The ST people won't appreciate my using their Combat 35 in RR when they provide a 40 for such going on, but for my money it will do. All this with the teeny 0.185 dia venturi insert. Consistency and hot performance aren't always contained in the same engine, but this one has 'em.
Thought for the Month. The hurrier you go, the behinder you get!
Posted July 4, 2015