VintageViews I
n my last column I mentioned the F&M ECHO transmitter that I had convert- ed to 2.4 GHz using a FrSKY module and Phil Green’s Single Channel En-
coder. I mentioned that I expected to fly my DeBolt Champ with this system before writ- ing this column. The encoder was set for “Compound” which gave me the emulation of a compound escapement with right and left rudder and up elevator with quick blip for throttle changes. Before attempting to fly the Champ with
this system I needed to get it out of my hangar where it has been hanging for sev- eral years and fly it first with my modern Futaba system. This was done primarily to determine the neutral elevator position as well as the engine rpm needed to sustain level flight. Since the compound emulator provided for three engine positions I deter- mined that the most critical position would be the intermediate position where I would be flying the plane most of the time. After several flights, I determined the
proper throttle stick position for “cruise” and then measured the rpm at that stick po- sition. I had replaced my Veco .19 with an OS .25LA because of the need for a very re- liable midrange setting. I also wanted the power of the .25 for the ROG takeoffs. The rpm needed was 6,700 and so I had to pro- gram the emulator to give me that throttle position at the intermediate setting. After a while I was able to achieve that
rpm by using the throttle setting of 20% mid-throttle. Phil Green programmed the emulator with mid-throttle settings of 20% up to 70% in 10% intervals. Well, I gave it the old college try but was
not successful with the ROG. Just how did we ROG those planes with escapements?
by bob noll You can reach Bob Nollvia e-mail at
bobrc@aol.com
PHOTOGRAPHY: BOB NOLL
This Mini Mambowas built from an Early RC kit and is powered with a Cox .049 with rotary exhaust throttle. This throttle works very well and a very low idle can be obtained. The plane was flown with a single channel transmitter converted to 2.4 GHz using a Phil Green single channel emulator. See text for flight results.
Maybe we never did. So I enlisted a fellow club member to give me a hand launch but that was a mistake. You just cannot find good hand launchers these days. After two attempts I decided that it was time to quit before the Champ got damaged. So, I went to my back-up plan and got my
rudder only Mini Mambo out of my van. I could do the hand launch by myself with this plane and proceeded to have three good flights. The first flight was launched with high throttle which I immediately recog-
nized as too much power and so a “punch” of the transmitter button got me to the 20% throttle setting which was just about right to keep the Mini Mambo flying in level flight. The only problem I had was that my neu-
tral rudder setting was slightly left and so most of the first flight was spent giving right rudder as the plane zig-zaged through the air. After a few minutes I decided it was time to land since my nerves were a bit in edge and so a “quick blip” gave me low throt-
The Bramco 10-channel reed transmitter with remote control box (above left) was made popular by Hal “Pappy” deBolt in the late ’50s. Bramco’s magazine ads stated that the stick box allowed the pilot to control the model with the reflexes and coordination of a real pilot. See text for details. Bramco’s Competition Ten receiver with Steeb servos (above right). Bramco’s magazine
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ad bragged about the “small size for low profile contest ships”. It measured 2 × 2½ × 3¼ inches and weighed 9 ounces without the 1½ and 45-volt batteries. Steeb servos were manufactured in Rochester, NY by Don Steeb and were considered one of the most reliable reed servos. A system such as this was considered very advanced in 1960.
OCTOBER 2012
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