Here's an add from Bertram Ponds book Expansion Engine Powered Model Aircraft. A ready made model powered by compressed air has made an appearance in Europe. The motor, tank and propeller are plastic. The wings and tail surfaces are balsa sheet. The tank at7 60 cu.cms. is a bit over 3/4 of a liter, and pressure relief valve set to 102 psi. (7 bar) The engine bore is .3937 (10mm.) and a stroke of .3149 (8mm.) The motor weighs .4 oz. (7gm.) The piston has a spring on top that acts as a pressure regulator. This results in increased duration. The propeller is 6.6 inches in diameter. Duration at 7 bar is 60 seconds. Weight of the entire model is 4.6 oz. (130gm) They have named the model Jonathan Z model.
Thanks Tom! I just made up some tools to bend reverse "S" hooks -the Harry Hitler type. Yours are intriguing also. I built myself a winding jig and have two planes to fly. I'm 62 and it will be my first attempt at it. Thanks for sharing..
Fantastic! The feeling must be incredible! Such a well trimmed plane and with all the complexities and challenges of the old explosion engines! Thank you for sharing and inspiring!
Amazing that Comet kits are still available. Plans are available on Outerzone. Record plans to a flash drive and have them enlarged to full size or whatever size is desired. Very few former and rib parts, mostly sticks, easy "scratch" builds. Good for free-flight or electric powered RC conversion. Recommend wing tip washout for lateral stability.
Yes, I think you are right. Best to do it on the bench as the engine is not easy to make fine thrust offsets with. Will have to use caution with any washin. Thx
@@tomnallen2 Tom, I mount my engines to a small aluminum plate. The plate is then mounted to the engine bearers on the airframe, I make several of these plates with different amounts of right thrust. Make trimming at the field much easier 🙂
First powered flights are always a nail biter, did I get the thrust settings right, enough power but not too much, and on and on until you realize that you lucked out and got it close enough to fly and give you a starting point.
Absolutely lovely. I couldn't have flown that well back in the days when I flew R/C planes! I had to look where you were from when I saw both Canadian and Australian registrations on the planes (I'm Australian).
Hi Glenn - thx. This diesel will go into a 36in span RN Models Consolidated PT-1 biplane. Did some beefing up (eg LG) as recommended in the kit. Building the dummy engine around the McCoy is a bit tricky, but coming together.
Thank you very much for this, I have just finished reading Farmers Take Flight by J I Granville and have learned a lot about the Gee Bees of which I am a fan and of 1920 -1930s air racing in general. The Thompson Trophy, Bendix and Schneider races are areas of great interest to me.
We used to have an air show at the airport in Ankeny Iowa in the 1990's. One day I saw the GeeBee fly over. I grabbed the kids and headed to the airport. I was a police officer at the time and I used to stop by the airport and shoot the breeze with the guys at the FBO. They let me sneak back and I grabbed a couple of pictures of the GeeBee with the kids. I understand that airplane is at the Oshkosh musuem now.
