telnar1236
Elite member
I've had my version 3 of my modular Gee Bee sitting on my shelf for a few months and just been too scared to try and fly it, since this was the last chance before I gave up on the design. The good news is it flies! Unfortunately, that's also currently the best thing I can say about its flight characteristics. However, it now shows enough promise for me to keep working on it and get it flying a bit better.
The 30mm fuselage extension shifted the CG far enough forward to make it flyable. In fact on the first flight of the day (video is of the second flight and I flew it a third time a bit later) it was a bit too nose-heavy. I think the issues I experienced during today's flights come from three sources. First, it was pretty windy at 17 mph and this is a plane with a 20" wingspan. Second, a small mistake I made while modeling the channels for the push rods limited the throw I could achieve on the elevator and rudder. I think the CG I had on my first flight was actually probably closer to what I want since it was far more stable and I just couldn't get enough throw to compensate for it very well. Third, the wing loading is quite high. This makes it pretty fast, but landings are... interesting. Issue 2 should be fixable and issue 1 wasn't a problem with the plane, but issue 3 is something I'll have to live with. Adding some form of spring or TPU suspension to the gear should help a bit with making landings less bouncy.
Now for the good news. First-off the changes to make this work a fair bit better are easy to make and fairly minor. I expect to have the final version ready to fly in a week or two. Second, this plane is exceptionally easy to print and assembly. It's only a couple hundred grams of filament and can be assembled in an hour or two. While the motor mount needs to be ABS to deal with the heat of the motor (especially in Florida) everything else is standard PLA. The power system is also one of the cheapest ones available and sold under about a dozen different brand names. While very much not a trainer airplane, for someone with a ton of flying experience, it could be a good introduction to 3D printing RC planes if I can get all the kinks worked out.
Also, so far as my other modular planes, I haven't forgotten about them. The F-104 remains one of my go-to jets and I fly it pretty much every weekend. The modular jet trainer remains in development, I flew it again today and it's getting where I want it to be. Should have more updates on it soon. And finally, I am in the process of putting together CAD for a 6s thrust vectoring jet that will also use the modular system. As I add more designs to the library of modular aircraft, I'm starting to get to the point where I can start sticking random parts together and experimenting.
The 30mm fuselage extension shifted the CG far enough forward to make it flyable. In fact on the first flight of the day (video is of the second flight and I flew it a third time a bit later) it was a bit too nose-heavy. I think the issues I experienced during today's flights come from three sources. First, it was pretty windy at 17 mph and this is a plane with a 20" wingspan. Second, a small mistake I made while modeling the channels for the push rods limited the throw I could achieve on the elevator and rudder. I think the CG I had on my first flight was actually probably closer to what I want since it was far more stable and I just couldn't get enough throw to compensate for it very well. Third, the wing loading is quite high. This makes it pretty fast, but landings are... interesting. Issue 2 should be fixable and issue 1 wasn't a problem with the plane, but issue 3 is something I'll have to live with. Adding some form of spring or TPU suspension to the gear should help a bit with making landings less bouncy.
Now for the good news. First-off the changes to make this work a fair bit better are easy to make and fairly minor. I expect to have the final version ready to fly in a week or two. Second, this plane is exceptionally easy to print and assembly. It's only a couple hundred grams of filament and can be assembled in an hour or two. While the motor mount needs to be ABS to deal with the heat of the motor (especially in Florida) everything else is standard PLA. The power system is also one of the cheapest ones available and sold under about a dozen different brand names. While very much not a trainer airplane, for someone with a ton of flying experience, it could be a good introduction to 3D printing RC planes if I can get all the kinks worked out.
Also, so far as my other modular planes, I haven't forgotten about them. The F-104 remains one of my go-to jets and I fly it pretty much every weekend. The modular jet trainer remains in development, I flew it again today and it's getting where I want it to be. Should have more updates on it soon. And finally, I am in the process of putting together CAD for a 6s thrust vectoring jet that will also use the modular system. As I add more designs to the library of modular aircraft, I'm starting to get to the point where I can start sticking random parts together and experimenting.
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