Monday, April 3, 2017

My Start in Co2 Powered Free Flight

Even though I work with new technology I find much appealing from the past, in my model aviation hobby I am trying some types of model planes I missed out on when I was younger. A friend had seen my blog article about Tales of an Ancient Modeler and sent me a message that he had some CO2 engines and maybe I would be interested in buying them. Of course I jumped at this but now I had much to learn; the fun part. With a book on CO2, two more books that included CO2, and some instructions friend Gary sent, I read about CO2 motors.

Air Hare with CO2 Motor

What I did not know is there is more than one size of CO2 cartridges and I needed the shorter size to fit in the holder for charging. With the correct cartridges I ran the two identical motors and it seemed easy at first but I still do not have the filling procedure mastered.  I grabbed a Guillow’s Cloud Buster rubber powered model and cut the nose off so a firewall could be installed. The next challenge was the mounting holes in the back of the motor were so small no screws I had would fit so I used pins with plastic ball heads bent over on the back of the firewall to hold the motor on. Not satisfactory but I got in a few flights with the Cloud Buster. The power seemed really marginal for the plane but it was cold and misty that day so plane was carrying moisture. Level flight was about the best it could do.

Wrong CO2 Cartridge
Cloud Buster

An airplane with more wing area and about the same weight sounded like a better choice, I had this model the “Air Hare” that a couple of students had designed many years ago. I cut the nose off and installed a firewall but now I had very tiny bolts sold with model railroad supplies. Worked perfectly but getting the tiny nuts on is a little tricky. I had to slide the nut over a pin and press that against the end of the tiny bolt to get it started. I was going to fashion a DT system but ran out of time before I had a good day to fly.

Tiny Bolts for Model Railroading

Correct Size Cartridges

Last Saturday was the nice day to fly and I wanted to try the bigger airplane. I had a little trouble filling the tank but then I got a good fill and gave it a launch. Up it went always climbing, it leveled off at maybe a hundred feet high and slowly glided down. There was little wind but it was drifting ever closer to a road. I was so hoping it would not land on the road or past that in the trees. It landed just on the steep bank next to the road, I was relieved. After walking around the tiny stream of water to retrieve my plane I decided this was enough until a DT system is installed.

Air Hare Climbing under CO2 Power

Air Hare Landed at Edge of the Road

Somebody asked why use a CO2 powered engine?  I think for me it has to do with history, my engine is a Brown engine, a design from Bill Brown who probably manufactured one of the first commercially available model engines which was a gasoline ignition engine.  He later sold his CO2 engines; there were other manufacturers of CO2 engines also. CO2 is quiet, clean, and normally reliable but so is rubber power or electric. For me it is another challenge in my model aviation hobby which keeps me interested, while briefly frustrated at times.

Bill Kuhl

Related Links

Bill Brown Biography AMA website -

My Old Article about the Air Hare -

Tales of Ancient Modeler Review -

1 comment:

  1. Very cool! You can always use the CO2 in your air rifle!