Radio Control
Sport-Aerobatics
Ron Van Putte
DID YOU ever have one of those years when it seemed like you were ready to break through in competition, but it never quite happened? So far this year in my pattern event (Advanced) I have managed to finish in fourth place not once or twice, but four times. The result is that I haven't yet earned a single advancement point in 1977. The final blow occurred when a competitor approached me at the New Orleans contest in October (where I finished fourth) and asked me when I was going to move up and make some room for others to win. Talk about frustration!
Apparently, we don't know all that we'd like to about nickel-cadmium batteries. I have been using a high-rate charger for the past couple of years and used to plug it in before bed, and unplug it just before going to the flying field the next afternoon. That usually meant that my batteries were charging for 12-14 hours at a time. Recently I began to detect deteriorating cells in my transmitters and airborne systems. In the space of a few weeks I had to replace two airborne battery packs and a transmitter battery pack because of lack of capacity. It took me a long time to discover that the problem was caused by the high-charge rate, despite the fact that the cells were supposed to be able to be charged at a high rate indefinitely. Apparently the high overcharge rate causes the batteries to overheat and progressively lose capacity. Then, I found out that Kraft had changed the charge instructions which are included with new radio systems. In addition, Kraft requested that dealers pass on the following instructions to customers:
"Warning: Before the initial use of your completed model, charge the batteries using the KBC-B for 6 hours. Cells charged at high rates should not be left on charge indefinitely. Maximum continuous charge time should not exceed 6 hours.
The initial charge time should be 6 hours if the system has not been used for a few days, and then charged one hour immediately prior to use. This will insure that the cells are kept in peak condition. When in doubt, return to a 6-hour charge before flying or operating the model. Remember, the failure to fully charge batteries prior to each flying session or operation of the model may result in the model becoming unreasonably dangerous to fly or operate and, thereby, the model may go out of control causing potential personal injury to others or to yourself as well property damage.
I discussed the battery charge situation with Bill Johnston (owner of Kraft Southeast). Bill told me that he charges his batteries for six hours after a day's flying and then puts the charge system on a timer which charges the batteries an hour a day.
I solved the problem in a different way. I purchased several of the older style Kraft chargers which have the separate pilot lights for the receiver and transmitter battery packs. In the high-rate configuration, a GE 1815 and 1816 bulb is used for receiver and transmitter respectively. However, if both bulbs are replaced with GE 1820 bulbs, the charger becomes a low-rate charger. Now I charge the batteries all night as I did before and don't have to worry about damaging the batteries.
You may want to check with your radio manufacturer regarding modifications to their charge instructions if you have a radio which is other than Kraft. Those nickel-cadmium batteries are too expensive to spoil by improper charging. I found out the hard way.
Every year, it seems, I report on unusual events that happened at the latest New Orleans contest. They always manage to come up with something strange like night flying (1975—Buzzard Bomb-shell flown with miniature flashlights and railroad flares), or weird bomb drops (1976—13 sort-of-fresh eggs dropped from an airplane with a special bomb bay). This year was no exception.
Dave Constant and Tom Golson put on flying demonstrations during breaks in pattern flying with matched Sure-Flite Products Piper J-3 airplanes. The J-3 is an all-foam airplane that requires little more than installation of an engine and a radio system, plus some paint to be ready to fly. They are definitely not sophisticated airplanes, but Dave and Tom put on impressive displays of formation maneuvers on Saturday. Tom followed up with night flights of his airplane using a chemical flare on one wing and two small flashlights on the other wing. The next day, the pair fooled most of the spectators by having Dave supposedly perform spectacular flights of both airplanes at the same time by using only one transmitter. Tommy was carefully hidden in the crowd with the second transmitter. They proceeded to top
120MA 3 WIRE SERVO MOTOR CHECK
For all you guys who wrote and phoned, here is the schematic for the Hugh Shoemaker servo tester, omitted from the December issue. A thousand pardons—and to you, too, Ron!
Radio Control: Sport-Aerobatics
Ron Van Putte
that by having a spectator (young, good looking, female) attempt to fly Dave's airplane with no assistance. The airplane suffered the indignity of many near-misses and a lot of staggering around—all actually performed by Tom who was still hidden in the crowd. We all enjoyed the shows and many of us got some good ideas for air shows of our own.
After building one of the new Royal Electronics Corp. 1/2A two-channel receivers, I'd like to thank George Myers for encouraging non-electronics-oriented R/C fliers to build one (Radio Technique, September, 1977). Mine went together very quickly and worked the first time I switched it on. In addition, I certainly agree that the four-channel conversion should be made before the integrated circuit is installed. The four-channel conversion only costs $1.95, so most builders will probably want to build it that way. A small soldering iron with a 1/16-in. tip should be used to preclude getting solder bridges on the circuit board.
At the New Orleans contest I talked to Stan John, the longtime contest director for the Crescent City R/C Club. We were discussing what it takes to have a popular contest. The poor contests don't last long—competition fliers pass the word about bad contests faster than they do about the good ones. The obvious criteria come to mind: flying site, contest administration, judging, weather, and food. By just about any standard, the CCRCC contest is a very good one. They just put on their 16th annual contest and obviously have the experience and knowledge to put on a fine meet. The October weather is great along the Gulf Coast; many say that it is the finest season of the year. The club puts on food fests on Friday and Saturday night which are free to contestants and family. So, Stan John and I were wondering why the New Orleans contests always have rather modest attendance. As for me, I kind of hope that the New Orleans Fall Carnival stays a well-kept secret for those of us regular attenders. Maybe that way I will have a chance to place there in the top three in Advanced next year.
Ron Van Putte, 12 Connie Dr., Shalimar, FL 32579.
Transcribed from original scans by AI. Minor OCR errors may remain.
