FREE FLIGHT OLD-TIMERS
Bill Baker 1902 Peter Pan, Norman OK 73072
Ignition-coil polarity
My brief paragraph in the September issue on ignition-coil polarity "sparked" some response. It is nice to get letters and find out there are people out there reading this stuff.
Jack L. Boone wrote in and described himself as a retired electrical engineer who used to design automobile test equipment. "You are absolutely correct when you indicate a 20% to 40% increase in performance by observing the correct polarity on the coil," Jack says. "All automotive coils were marked for polarity." Jack will be happy to correspond with anyone who wants to discuss ignition systems; his address is 114 Conrad Ct., Mukwonago WI 53149.
Another well-qualified gentleman with an M.S. in Electrical Engineering, Floyd Carter, says that while the battery-voltmeter test described in the September column will work to identify which primary terminal is connected with the high-voltage winding (to determine polarity), the difference is minimal in terms of coil output—Floyd says it's approximately 2%, not the 20% to 40% claimed.
He goes on to say, "There's a very good reason why coils are not polarity marked. It simply makes no measurable difference." For those who want to communicate, Floyd's address is 2029 Crist Drive, Los Altos CA 94024.
"Well now there then," (as James Dean said in Rebel Without a Cause) I have two conflicting statements from the experts. One says the difference is insignificant for all practical purposes, the other says the indicated significant gain is true. What to do? Yell for help!
I asked Jim Alaback, as he had added some original material to an item that had been passed from newsletter to newsletter. I am sorry that I didn't credit The Orbiter newsletter or Jim in my column, but it was unclear who had originated the piece. Jim credits Bob Laybourne; the original article was in The Ignition Manufacturer's Institute.
Jim says everyone is right, in a sense. It is true (as Floyd Carter says) that there is little difference to the coil as to which way the battery is hooked up. It makes a significant difference, however, at the spark plug. The spark plug will require less voltage to fire if the polarity of the coil is correct, as it "requires less voltage to fire from the high-temperature center electrode to the cooler outer one than if the polarity was reversed." Jim continues, "This seems to be analogous to vacuum-tube technology, where the negative plate is heated to expedite the release of electrons to the positive plate." (Jim Alaback is the Old-Timer columnist for Flying Models magazine.)
Hand-launched gliders
Onward through the fog. In the last column I wrote about hand-launched gliders (HLGs). Bob Larsh has a list of the OT HLGs he has available; $1.25 will get you the list and a sample plan. The plans cost between 50 cents and $1.25. In my opinion, the most competitive gliders are the Hervat and Hugulet designs, and Casano's Zoomer.
NFFS Nostalgia rules
Bob has finished the sixth revision of the National Free Flight Society (NFFS) Nostalgia rules and a list of the eligible gas models. This will cost you $3 plus 64 cents for stamps, or $3 and two stamps, or $3.64, whichever comes first. The NFFS Nostalgia events cover the years 1943 through 1956. The rules on eligible engines are complex, and I highly suggest that you study this booklet closely if you intend to compete. Bob's address is 45 South Whitcomb Ave., Indianapolis IN 46241.
From Walt Rozelle
I think my OFB (Old Flying Buddy) Walt Rozelle will forgive me if I share part of one of his recent letters with you. Like many of us, he sometimes goes to a contest out of practice and tries to fly out-of-trim models:
"I demolished my excellent-flying 'Iva' (a Galbreath CS-powered Astrostar) because I didn't start the timer at launch. It went way up, came way over the top, and went way down—straight in, going at incredible speed. Hank Nystrom was standing nearby and commented, 'Good wing construction. It didn't flutter once.' Thanks, Hank.
"Later, I asked Hank to check the engine run on my A/B Pilfered Pearl. When the engine quit Hank said, '42.76 seconds.' Thanks again, Hank. The model was just a dot in the sky.
"I thought it would be a good time to get some practice on my Walston retrieval system. I turned the receiver on and discovered it had lost the charge. Later it was found to have two bad cells in the battery pack.
"When the model was found, I discovered that after fueling the bladder, instead of running the fuel line through the cutoff mounted on the engine lug, I ran the line through the other hole in the lug!"
Transcribed from original scans by AI. Minor OCR errors may remain.
