3D Printed MiG 15 64mm EDF Jet (Modular Plane)

[telnar1236]

I haven't had too much time for building lately, so I've been doing a lot of designing instead. One the goals of my modular plane system was to be able to swap out the power systems on the jets for either a 64mm unit or a 70mm unit, but both the F-104 and modular jet trainer were too big and heavy for a 64mm unit to be effective (though I think the jet trainer would probably actually be fine with one after some testing with throttle limits on the 70mm and I plan to test it eventually).

So, I decided to build an adversary for my F-104. I chose a MiG 15 for its small size in comparison to most jets and stubby fuselage which meant it was practical to use the modular geometry without adding a lot of weight. It's a simple 3 channel design plus a 4th channel steerable nose wheel. There's nothing too crazy to talk about and it uses the same techniques as most of my other designs. The wing uses a Clark Y airfoil with 4 degrees washout which should give it a fairly gentle stall and the structure is printed as a single wall of ABS or PLA. The AUW should be about 1200g which will give it a thrust to weight ratio of just below 1 using the Powerfun 64mm fan it's designed to fly with. It should fly on a 4s 2200 mAh - 3000 mAh pack.

The fuselage is a bit stretched and I decided to go with the canopy from the 2-seat version since I don't think I've seen it modeled. I may also model a single seater canopy if it flies decently well. The nose gear is also farther back than scale since I need to be able to access it to install the servo.

I have a bunch or red filament sitting around that I need to use so the plan is to build everything in red (it is Soviet after all).

 

[Mr Man]

Sweet!

 

[Mr Man]

Very Cool Design

 

[telnar1236]

Here it is mostly assembled. I'm pretty happy with how painting over clear PLA worked for making the canopy.

One of the more interesting features of this design is the split EDF duct. Even though the air comes in through a single inlet in the nose, the duct immediately splits in two to give room for the battery and nose gear hardware. This is a feature this RC model shares with the real MiG 15 - something I only learned when doing some background research to design this plane.

 

[bisco]

beautiful!

 

[Mr Man]

WOW! Great Job on that design!

 

[Mr Man]

Have you tested it yet?

 

[telnar1236]

Have you tested it yet?

Things have been a bit busy, but I have tested it a few times, but have not had time to get video. Had some issues getting the CG to work out, but once it was balanced it flies ok. I'm used to shorter wings where you can land at a high angle of attack, so I struggle to get the plane to slow down enough, but it's pretty easy to fly otherwise. It doesn't have a particularly high stall speed for a jet this size and design, and could probably even be hand launched, but it just doesn't want to slow down and glides forever. The bell crank on the tail has a bit too much play so it doesn't like to fly inverted with anything less than full throttle. On the other hand, it's very stable and has plenty of power for loops and other vertical maneuvers. It's also very precise in how it flies, so while I normally struggle with getting precise neat-looking full Cuban 8s, I can do them pretty easily with the MiG 15, even in high winds.
Overall, it needs some work before I'll be totally happy with it, but it's well on its way to being something I'm very happy with. When I have some time, I'm going to add in split flaps so that it slows down more quickly. The gear also needs to be beefed up. I'm not sure if it's my bad/fast landings with this plane or if the gear is just too weak, or if it's a combination of the two, but most times I've brought it out, I've needed to replace one or more of the struts afterwards.

 

[Mr Man]

split flaps sound like a good idea to me!