Ray's Home Page 1

Airplane Modeling
From Rubber Band Power to Radio Control Gas

      (Long, read only if you have the time or the interest in this hobby)

This is a work in process
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This is a history of one of my hobbies over the last 75 years. I don't remember what I had for a hobby until I was about nine years old, but I do remember that I started to like to tinker with how toys were made and to want to build (create) something on my own about that time.

The first project that I can remember was a rubber band model of an airplane that was given to me by a gentleman (whose name I recall as being Russ) that taught crafts at the school gym in Dearborn, Michigan on Saturday, to allow the children in the neighborhood to have something to do to occupy their time. I am sure now that the program was sponsored by the school system, and the gym, hallway and playground were used for this purpose during the summer vacation months only. Some of the children played baseball, some played basketball, some played a form of kickball in the gym and the crafts were located in the hallway alongside the gym. This is where I was first introduced to the wonderful world of modeling.

There were about six of us that would go there every Saturday to continue to work on our projects, which Russ kept with him all during the week, so it took quite a while to complete an airplane that was built up of a lot of 1/16 inch square by 12 inch long pieces. On Saturday I just about couldn't wait to get my home chores (dusting, scrubbing the bathroom floors etc.) done and head for the school. During the following summer, I had built an airplane that Russ said was good enough to take to a rubber band free flight contest at the Selfridge Air Force base at Mount Clements, Michigan. I didn't win anything but it sure got the adrenaline going.

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After a couple of years I talked my Mother into buying me an Ohlsson 23 engine so that I could build and fly a gas powered free flight model. I built and flew class B models, off and on, for the next 3 years. Russ would pick me up early in the morning and we would drive out to a sod farm at Eight mile road and Southfield road, where we could fly with about a 5 second engine run and still be able to retrieve our models. We would also go out there in the evening when the air was cool and still to fine-tune our models.

circa 1939

This is the sod farm that we flew at during my free flight days. I believe that the plane is a pylon kit with a modified elliptical wing. It was powered by an Ohlsson 23 ignition engine, using gasoline mixed with a little bit of 30 weight motor oil. During contests we would inject some castor oil with nitromethanol into the intake, which would give the engine a boost for the 20 seconds before the air timer would cut the ignition to stop the engine within the allocated run time.

One weekend we drove down to Toledo, Ohio to a national contest. At the contests you were allowed a 20 second engine run and the total air time was recorded. The last that I saw of my model was a speck a half mile high out over Lake Erie. I never did get it back even though I had my name and address taped inside in case somebody did find it. I lost most of my contest models since the 20 second engine run put them up high enough to catch thermals or upper air drafts.

I did get one of my planes back after a contest at the Henry Ford Airfield in Dearborn, Michigan. The fellow that found it tried to run it on pure gasoline, so the engine was warped and seized up, and was useless. The plane was still in good shape so it wasn't a total loss. I thanked him and asked him what he would like as a reward, and he said he was glad to be able to do me a favor. I guess he was embarrassed about ruining the engine. I never heard from him again.

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In 1936 I started school at the Henry Ford Trade School in Dearborn, Michigan and was too preoccupied to pursue my modeling hobby with any consistency. I was able to do some modeling in free flight and control line, and I still have a McCoy 35 Redhead in a drawer in my bench and a K&B 35 Torpedo Greenhead that is installed in the profile plane that I have pictured later on in this article. After graduating from HFTS I was drafted into the army and spent the next 3 years servicing Uncle Sam. After I was discharged, I took advantage of the GI Bill and went to college at Tri-State College in Angola, Indiana. Tri-State is a trimester school, so for the next two years I was away from home and didn't get a chance to do any thing but study. Next came marriage and two children which kept me pretty busy with part time jobs while trying to finish my education and just keeping my head above water. I finally gave up and got a full time job.
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As fate would have it, there was a toolmaker in our experimental shop that was a modeler and also a Ham Radio operator (Art Ryan). Well, we had some great discussions on taking our free flight airplanes and mounting a radio into them for some flight control. Our first attempt was a transmitter that was on the ham band, made out of surplus electronic gear (mostly obsolete army and air force radio gear) that we picked up at the electronic surplus store. The transmitter was assembled in a metal box about 6x8x10 inches in size, weighing about 10 pounds and had an antenna that was tuned to the 6 meter ham band for my ham buddy. Mine was tuned just a hair lower which put it into the 25 megacycle (CB) band. A tuned and matching crystal and some peanut tubes with 3 different battery voltages comprised the receiver, that was all hand wired and soldered, and weighed about a pound.

Most of our first flights were disastrous and it would seem that we would lose control at about 100 feet. We kept improving our receivers until we could keep control for maybe 500 feet which we thought was a great accomplishment. The original escapement was a Bell Telephone ringer coil as a solenoid, with a split armature pivoted above the coil, a 3 pawl armature wheel mounted on a shaft running under the coil and through the fuselage, with a loop on the end that would fit over a pin in the rudder. Each pulse would pull the armature in against the core of the solenoid and allow the wheel to rotate, first one quarter of a turn (left rudder) and  then one half of a turn (right rudder) and upon releasing the button it would rotate one quarter of a turn, which would put it back into the neutral position. The catch on the back of the split armature would restrain it until the pulse was released.  The shaft was be rotated by means of a wound rubber band, to give either a left or right control, until the rubber band was unwound to the point that it wouldn't have enough force to move the rudder..

circa 1951

This is the same sod farm, and we gathered here on weekends to try out our radio gear. You can see the transmitters (black boxes with 9 ft. antenna) lined up in front of the cars. I am holding up a Bootstrap with a 5 ft. wingspan, powered by a McCoy 35 Redhead. The silver plane behind me belonged to my ham buddy and was a Curtis Robin (as I recall). It was a sweet flying freeflight plane and turned out to be a great RC adaptation. Both of the planes were controlled by our own home built radios and by the three position escapements. Left, Right and engine control.

We were continually trying to improve our radio control and soon we were working on a system where we made an escapement that would have a third position. This was accomplished by putting a tab on the wheel just before recentering, which had a contact on it that would allow a current to flow through a solenoid and a 1-1/2 volt battery. A two pawl, rubberband driven armature similar to the directional control escapement was connected to a lever on the exhaust manifold bar to open and close the exhaust manifold. The manifold bar was a brass bar enclosed in a piece of copper tubing. The copper tubing was soldered to a brass plate and then the whole assembly was cross drilled through, so that in one position the holes were open, and 90 degrees from that, the holes were in a position that it would restrict the outflow of the exhaust gas to a great degree and slow the engine down. In other words, it choked the engine to an idle. This was quite an improvement since you could now slow the engine down and try for a controlled landing. Previous to this you had to try to fly until you ran out of fuel and then land "dead stick".

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Another attempted improvement was the design of a "pulse proportional" system. This consisted of a Mighty Midget motor that had a wheel soldered to the motor shaft. There was a pin on the wheel, offset by about 1/2 inch from the center of the motor shaft, and it was restrained to one side with a rubber band. A shaft running from the rudder with the same configuration as the earlier control passed over the Mighty Midget motor and had a loop down that just fit over the pin in the wheel. When the motor wanted to run it would pull against the rubber band and the pin would move the shaft to the center of the wheel axis which would be a neutral position. By giving the motor full power, the pin would move another 60* to the opposite side. By pulsating the voltage to the motor, a positioning of full right to full left could be had in proportion. The pulsating was accomplished by having a motor running in the transmitter box that had a large drum of a nonmetallic substance on which was mounted a triangle of copper sheet metal that was bonded to it. At one end of the drum you would have almost no contact and on the other end you would have almost constant contact. In the middle you would have contact one-half of the time. This would be the neutral position of the rudder. By moving the contact lever over the drum you could get any value of control that was desired.

This system seemed to be the cure all for "proportional control" but in reality was much more bother than it was worth, since everything had to be synchronized to a tee for it to work as desired. It seemed that most of the flights ended up with the plane in a left bank death spiral until the ground put a stop to it. Even with new batteries replaced every flight a flight of more than a few minutes drained the batteries so much that the receiver couldn't follow the input pulses. More flights were disastrous with this system than the previous one which isn't saying much for either, but that was the way it was back then.

This was about the time that my company duties didn't allow for a hobby distraction since customer satisfaction and entertainment was now the priority. This was also about the time that the reed receivers were coming into the system. My ham operator buddy got one but was very disappointed with it since the allowable transmitting power on the RC bands was so slight that even the reeds had a lot of problems.

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My next sortie into Radio Control Airplanes didn't occur until I was retired. My oldest son David surprised me on my 66th Birthday with an Academy of Model Aeronautics membership and a few of the latest model magazines. Flipping through the pages of the magazines piqued my interest enough to get me to look into the hobby again. One of the biggest surprises was the cost of the equipment, especially the radio gear. Also, I noticed that there were an awful lot of model accessories for everything from models to engines to radio gear. I think that the greatest change was the extent of the models, from the kits to the Almost Ready to Fly models and everything in between.

My first RC model this time around was an ARF Right Flyer 40, a 5 ft. wing span plane from Hobby Shack with a Magnum 40 FP (ABC) engine and a Futaba 6 channel radio system. By the time I had all of the gear that I though that I would eventually need, and really wanted, this first order ran over $650. Of course, I got a number of items that I knew I would need once I got into the hobby with both feet and that ran the cost up almost double. You'll notice that I bought 6 channel radio gear just in case. They told me at the club flying field that I could get started for about $350 which I think was about right.
 
 

1989 - This is a picture of that plane after I completed the assembly and before the first flight.

I hadn't realized that I was not as coordinated in using my thumbs for flight control as I thought I would be, and there was a period of about 50 lessons on the "buddy" box before I was given the go ahead to complete a take-off and landing on my own. After that, I practiced take-offs and landings in both, right and left directions, until I was quite comfortable with my ability.

I found out very soon that I was very anxious to make modifications on the model, as I had done ever since I built my first model, and when a "mishap" occurred, I was able to modify the monocoupe into a mid wing which performed slightly better in stunt maneuvers than when it was a high wing monocoupe. I also got rid of the rubber bands as wing hold downs and replaced them with a 1/4" dowel and two nylon bolts. I still have it, and if I haven't flown for a while, I will fly it until I get comfortable with the feel of the controls and my visual perception. It's really my workhorse now.
 
 

Here is what it looks like after the modification.

It is now a mid wing with all new covering material and 4" foam rubber wheels. The large diameter wheels are for flying off of rough gravel or grass that is cut with a Bush hog. It has been changed so radically that everyone would ask what model it was. I finally named it DON'T ASK and now visitors answer their own questions. The yellow wing panels are for orientation since the bottom of the wing is the burgundy color. When the plane is banked, the top of the wing flashes the yellow color for visual orientation. The wing tips are squared off with turbulator tabs. The engine is still the original Magnum 40 FP which must have at least 500 hours of running time, and it still starts with a finger flip or two of the prop, runs with plenty of power and idles beautifully.

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