Control Line: Racing
ROSSI .15 REWORK. I have had several letters asking about the crank pin replacement on the 10.5mm Rossi .15 crank. I am sure many of you have had the same problem I have had with the pin shearing off or coming loose in the crank. I have a couple of the re-pinned crankshafts, and I have run one with excellent results. Mr. Al Herda, 1417 N. Dunton, Arlington Heights, IL 60004, has been quietly doing these. He uses an electrical discharge machine (EDM) to make a new hole for the crank pin. He braze-welds a new high-speed pin; offset grinds the new pin, and machines a new counterweight band and sweats it on the casing. In addition, he will overbore your crankshaft to any diameter and will guarantee no distortion. This certainly will rejuvenate the rather expensive crankshafts and put some of your "retired" Rossis back into service.
AMA Nats 1983: CL Racing
THE 1983 NATS is now in the history books. The Racing events were as exciting as ever, and the site the best that the competitors have had to fly on in recent years. I must say that the circles were table-top smooth with very few irregularities, and the Air Force personnel did an excellent job installing barricades at both the front and rear of the circles to keep the spectators at a safe distance. Since the townspeople of Chicopee are supportive of Westover Air Force Base, many thousands came out on a daily basis to observe all the competitive activities. At one point during the Rat Racing finals, I counted over 200 spectators at the circle. I also noticed unusually large numbers of people at both the Speed and Stunt circles.
Control Line: Racing
CALCULATION of tank volumes. I have had several requests from Racing enthusiasts for a way to calculate the volume of a fuel tank which has been constructed to fit in the available space on his aircraft. I know we have all done it at one time or another and later found it either had too low a volume or carried too much additional fuel, adding unneeded weight when the Racer was put into competition. The first item is to measure the volume of fuel your racing engine uses per minute. Obviously, we know approximately how long the races last; consequently, we must anticipate how much fuel the engine will use during the racing sequence. I first take the engine which I will ultimately use in my plane, mount it to a test stand, and using a tank of known volume, measure how much fuel is used per minute at racing rpm with an appropriate propeller.
Control Line: Racing
SLOW RAT. The discussion of Slow Rat rules and the lack of participants at the Nats brought a large response in my mailbag. Heretofore, we have been mentioning the various "modifications" of Slow Rat flown in various localities around the country. I have received several letters illustrating rule modifications to the aircraft and engine, but also several requests on the type of tanks and proper pitting procedure for the Slow Rat. First, fuel tanks. During my participation in this summer's contest circuit, I took several pictures of various types of Slow Rat or Sport Race aircraft and the type of tank arrangements which were incorporated on the model.
Control Line: Racing
IMPROVEMENT of airspeed is the subject this month. I have had several letters concerning the apparent inability of racing competitors to get their airspeeds up to the competitive level. Subsequent correspondence has indicated that their engine horsepower and propeller combinations are creating the proper thrust to achieve competitive velocities. What's holding them back? One major hindrance to airspeed is engine vibration. We don't see much of this in the Rat Racing event since, I believe, all competitors are using the "Harter's" magnesium pan, which virtually eliminates power-robbing engine vibrations.
