Control Line: Racing
John Ballard
.21 Racing
Let's look at .21 racing. Last year at the Nationals we had at least two pseudo entries in .21 Rat Racing, and last fall several competitors built these little aircraft. We found that many of the nylon, store-bought propellers were quite satisfactory, and the engines performed well on 10% nitro. It is my understanding that several Midwest contests this year will feature .21 racing.
My old speed colleague, Al Stegens from Cleveland, sent me a .21 "Fun Speed" event flyer for a contest on June 15 in Cleveland. Fliers utilize 10% nitro, solid lines .016-inch diameter, 60 feet long, and time for seven laps. At the bottom of the contest circular, Al wrote: "An event where a super-human effort would not be necessary." I think this aptly explains .21 racing: the little planes fly about 75–80 miles per hour, the propellers, engines and tank accessories have a reasonable price tag, and there are at least 10 different .21-size engines available. Replacement parts are no problem, and the performance/starting ability of these engines seems to be as good as their high-performance counterparts.
I know that some of the racing enthusiasts in the Dallas/Fort Worth area are planning .21-style racing, and I would be interested in hearing from anyone else who is planning a contest during the 1986 flying season.
Archives: 10cc Racing Engine
One of the "old school" competitors sent me an advertisement from a 1948 magazine (I believe it was Air Trails). It advertises the "new" Black Panther racing engine. The ad cries out: "Screaming streak of FURY!" — "Vicious and diabolical" — "Deadly to all competitors" — "Absolutely the hottest piece of iron to ever hit the track!" I have never heard of an engine being called "vicious" and "diabolical" and having only a $35 price tag. It is my understanding that the engine was used for race cars, boats, and speed planes of that era. The brochure goes on to indicate that an individual would receive excellent power and stamina necessary for a winning performance without "dinging" or "hopping up" this particular powerplant.
Engine Vibrations on Scale Racers
I have had several letters commenting on problems of scale racers vibrating with the high-performance .15 racing engines. In checking with several major competitors, I find that many of them use a 3/16-inch magnesium plate sandwiched internally in the profile fuselage. By carefully drilling holes to lighten the magnesium, they use this vibration-dampening plate over the full frontal area, including approximately an inch behind the leading edge of the wing. By carefully mounting this plate during construction of the profile body, vibration is held to a minimum.
At the 1985 Nats, several competitors experienced engine vibrations when the "10% nitro rule" required them to use small, high-revving propellers. One competitor improved his situation by using a small X-Acto knife to carve out an area and install an additional magnesium mounting plate. By merely installing this plate, a 0.2 to 0.3-second improvement in lap time was obtained. Also, it is most important to mount the engine with 4-40 mounting screws made of hardened steel, not the softer screws generally available in the marketplace.
Half-A Mouse Racing and Flight Boxes
During our Midwest flying season we had several contests featuring Half-A Mouse Racing. One important problem I noticed was the general lack of proper marking of the shorter mouse-race circle. The markings on the 60-foot circles for Rat and Scale Racing were quite adequate, but for the little Mouse Racers the circles were often poorly marked, and a series of unfortunate accidents occurred.
I am enclosing a picture of a type of flight box many junior and senior competitors use with the Mouse Racers. Competing in this event seems to require a great amount of glowhead changing, plus the availability of many props, fuel bulbs, and other accessories. Keeping all this at hand requires a flight kit that, in many cases I've seen, would also serve a competitor in Rat or Scale Racing. At any rate, the flight kit is awfully large compared with the size of the model and can be cumbersome to move.
When the circles are improperly marked, it is very easy for a competitor to land and hit a flight kit, resulting in a damaged propeller or a broken wing. This often ends the competition for that plane for the day, since the wing tip gets smashed and cannot be properly hot-stuffed back in place.
In the confusion of a pit stop—filling the little engine-mounted tanks, installing the proper glow plug attachments, and dealing with spring starters—it is easy for the pit crew to leave the pit box containing accessory items in the flight path of other competitors. In one case I noticed a flight box so far into the circle that when one competitor landed his line snagged the carrying handle of the case and pulled the pit box into the circle. I noticed this happening with the Open competitors as well as the Juniors and Seniors.
Upcoming: Midwest Sport Racer
Next month I will share plans for a Midwest Sport Racer. This is a consolidation of the various designs I have seen flying in the Midwest. This consolidation should give you a very stable and decent-flying sport racer.
As always, your comments are appreciated.
John C. Ballard 10102 Kimblewick Dr. Louisville, KY 40223
Transcribed from original scans by AI. Minor OCR errors may remain.
