Live Wire Kitten. Radio control model for electric power with Speed 400 motor. Wingspan 34 in, wing area 220 sq in.
Quote: "An electric replica of Hal DeBolt's Live Wire Kitten, by Bob Aberle.
Bob Aberle, some 40 years ago (above left), poses with one of several deBolt Live Wire Kittens he had built since 1953. It had a 2-tube receiver and a McCoy .049 diesel. Now it's 1996, Bob is gray (above right), and his newest Kitten uses an electric motor, has a modem 4-channel receiver. and plastic covering!
Once upon a time it was the R/C trainer of choice. The author gained his R/C wings with it and pays tribute to it with this remake. Takes an inexpensive Speed 400 motor.
If you are in your late fifties (or older) and have been in the model aviation hobby since school days, you will likely remember the little Hal DeBolt designed Live Wire Kitten (oz275). Hal kitted this plane under his company name of DeBolt Model Engineering Co, or DMeco as it was called, in 1953. The company back then was based in the town of Williamsville NY, near the Niagara Falls area.
Just to back track a little: in the early fifties, the only form of R/C flying was done on the HAM radio bands. If you wanted to fly the primitive R/C systems of the day, you also had to study to obtain a HAM license. I'm going to guess, but around 1952, the FCC released a frequency of 27.255 MHz, which could be used, among other things, for the control of model aircraft (and boats as well). If my memory serves me correctly there was initially only one channel assignment, although later some five or six channels were assigned in the 27 MHz band.
Although a permit was required from the FCC, no test was necessary. Almost overnight circuit designs began appearing in the magazines, authored by such famous people as Howard McEntee, Ed Lorenz, John Worth, and others. Several commercially manufactured R/C systems appeared at the same time, but for the most part it was buy the parts and build it yourself.
With the possibility of radio control systems now being in the hands of the average modeler, the next urgent need was for new aircraft designs that could explore the ad-vantages of remote control by radio. In the 1952 and 1953 time period several popular designers of the day, who had been involved with freeflight and control line model designing, took up the R/C challenge. People like Hal De Bolt, Lou Andrews, and Norm Rosenstock made it happen back in those days.
Probably the first successful R/C single-channel, rudder-only controlled model design to be mass produced in kit form was the Hal DeBolt designed Live Wire Trainer (oz5554). I'd have to guess that thousands of these models were built and flown successfully. The typical radio receiver of the day consisted of a single hard or vacuum tube or a single gas tube. When the radio signal was 'broadcast' from the transmitter, the plate current of the receiver tube circuit would change slightly (usually it would go down a few tenths of a milliampere). That change in current was just enough to cause a sensitive relay to open and close, thereby operating a small solenoid device, which was known as an escapement.
The escapement, in turn, was driven in a rotary motion by a twisted rubber band. Each signal from the transmitter, caused the escapement to rotate, providing rudder control in sequence, e.g., left, neutral, right, neutral, and so on. Radio system ad-justments were critical, as were the relay contact adjustments. The batteries, which were not rechargeable, didn't last very long. And then you always had to worry about having enough turns in the rubber band to maintain rudder control for your landing. Despite all of these early problems, the DeBolt Live Wire Trainer with a small .09-.15 size glow engine was a very popular design.
By 1953 radio control technology of the day got a big lift from Mr. Ed Lorenz (who now resides in Ft. Myers Beach, Fla.). Ed developed a twin tube receiver that he published in the February 1953 Model Airplane News (I have Ed's autograph on my copy of that issue!). The twin tube concept allowed the second tube to be biased at essentially no current, without a signal coming in. When you keyed the transmitter, the first receiver tube's plate current changed slight-ly, but the second tube's current would jump up to 2 or 3 mA. That large increase in plate current made it possible to go to sub-minia-ture relays, without the need for any sensi-tive adjustments.
A full airborne system could then consist of a 1-ounce receiver, two 22-1/2 volt hearing aid batteries in series for 45 volts for the plate or 'B' supply. Two AA size pen cell batteries in parallel heated the tube filaments and two more AA size pen cells, in series for 3 volts, operated the escapement. I'm going to guess, but the entire flying weight of that Lorenz airborne system was probably not more than 7 or 8 ounces.
With a very lightweight and reliable single channel R/C system now easily obtainable, the genius of hal DeBolt went to work to produce the tiny (34 in span, 220 sq in area) Live Wire Kitten. My first RC model in 1953 (age 15) was the Lou Andrews, Guillow Trixter Beam (oz2864). By the end of 1953 I had my first (of many) Lorenz two-tube receivers built and installed in my first DeBolt Live Wire Kitten. The radio proved remarkably reliable for its day.
As a result, that first Kitten enjoyed several years of flying. It was powered, as were all of my Kittens, with a McCoy .049 diesel. Total weight, as I recall, was very close to that specified on the plans, namely 18 ounces. A typical flight lasted about five minutes. The motor would run about 4 minutes and if you had a little altitude, you generally got another minute or so gliding in for a landing. Despite the rudder only control, the Kitten could be spun down to gain speed, after which the application of opposite rudder would produce a couple of 'high speed' loops. With rudder only, and non-proportional at that, you always had to anticipate your control application. Of course, you also had to keep in mind whether right or left was the next control in sequence. But we managed in those days and we also had fun.
Modern day Kitten. Back around 1957 I built my last Live Wire Kitten. I was 19 at the time and already working in the defense industry, while at-tending college at night. During a lunch break a fellow worker took several color transparencies of me with my Live Wire Kit-ten. I've kept those color photos for close to 40 years, looking at them every once in a while, with the thought that it would be nice to revisit the Kitten some day.
Well, a little over a month ago I pulled out my copy of the original plans and began to construct another Live Wire Kitten. I might tell you that the plans and die-cutting tools for most of the DeBolt original kits are now owned by Don and Ron Wilson of Easy Built Models (PO Box 425, 210 Walnut St., Lock-port, NY 14095). I spoke to Ron at the recent WRAM Show and he was thrilled with this revisit project. Ron did indicate that some day he might possibly produce kits once again for the Kitten. But in the mean time, he had no objection to anyone building a ver-sion to the updated plans contained in this article.
As you must all know by now, I have pret-ty much settled on electric power models exclusively. So it was only natural to make this new Live Wire Kitten electric powered. Who would have thought 40 years ago of this possibility and the fact that it could be so in-expensive and yet so practical. The Kitten, as you see it portrayed in this article, is about as close to the original in size and structure as possible. I wanted to preserve all the original lines as best I could. The photos accompanying this article tell the structure story in great detail. What I will try to do is explain the finer points, the details of the electric power system and the radio system and its installation in the 'new' Kitten. Keep in mind that although I wanted to be a purist, the limits of most flying fields prompted me to use rudder, elevator and motor control -something I would have loved 40 year earlier!.
Construction. I felt it would pay to use a very thin 1/64 ply doubler on the inside nose area of the fuselage. The bottom fuselage sheeting ends by the trailing edge area of the wing. Aft of that point, out to the tail, is strictly the iron-on covering material. The stab is cemented in place. The elevator is one piece so that a joiner was not necessary. Both the rudder and elevator hinges are made from the covering material. To connect the servos and the control horns I simply used .025 inch di-ameter wire as a pushrod, supported by pieces of yellow inner Sullivan Gold N' Rod tubing..."
Live Wire Kitten, Flying Models, June 1996.
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