3D Printed Jet Trainer - 70mm modular EDF Jet


Elite member
This is the second plane in the modular airplane series I am working on. It's a jet trainer designed to be a good first EDF. Now that it's printed and I've had the time to do some testing, I think this plane deserves its own thread where I can go into more detail about it.
The goals of this plane were as follows:
  • 70 mm jet powered by the same 4s Powerfun fan, 60A ESC, and 4000 mAh 4s pack as my F-104 and using the same EDF fuselage
  • Easy to fly, stable, and easy to fly slow with a gentle stall
  • Simple 4-channel setup requiring minimal effort
  • Grass capable
  • Entirely PLA structure with no supports required
  • The wings and tail can be switched out easily to get different flying experiences and to make experimentation easy
This is what it looks like.


And here is some flight video where another member of the club flew and I filmed (I suck at videoing).
The plane has extremely gentle characteristics all around and flies more like a warbird than a jet in many ways. The combination of a wing fence and a vortex generator on each wing makes the stall exceptionally gentle, ensures continued aileron effectiveness, and increases lift by about 20%, so the plane can fly around in high alpha with ease.


And the large wheels let it both take off and land in taller grass than most 90 mm EDFs can handle. Overall, I'm pretty happy with it, and it should be ready to release soon. Here is what is left to do.
  • Redesign aileron hinges - all 4 hinge points broke while I was handling the plane on the ground at one point or other.
  • Model strake on vertical stabilizer in CAD - currently it's just a piece of foam board I added to increase directional stability.
  • Increase rudder size - the rudder is a bit small and not as effective as I would like.
  • Reprint in a different color of PLA - the black PLA is hard to maintain orientation with, and in the Florida sun it was already experiencing warping due to heat. While it looks cool, the black PLA will not be able to stand up to a Florida summer.
It shares the nose fuselage and EDF fuselage with the modular F-104, and it is also possible to put the T-tail from the F-104 on the jet trainer, although the jet trainer tail cannot be installed to the F-104 tail fuselage. In the future I plan on making a core fuselage variant for the jet trainer that will allow the F-104 wing to be installed, so that I can test changes to the F-104 without risking the more complicated to print F-104 itself and its retracts.