Mig 29 Twin 50mm EDF Build

[Burkeomatic]

Here are build instructions for my Mig-29. It is a pretty straight forward 4 sheet DTFB build.



It takes 2 50mm qx motor 4700kv EDFs. If you power both EDFs off one battery, ensure that you have one with adequate C rating. Even though it shouldn't have, I puffed up a 2200mah 50c battery.



You should be able to put this plane together for less than $100 bucks. Yes, a twin engine rocket ship EDF jet for less than $100! The EDFs are $40-50 for the pair, and I just use generic $8 40A escs from aliexpress and 2 9g servos. The only way you might hit a snag is if you don't have the 4S 2200mah batteries, but this plane with these motors will fly on 3S so you should be good! This could also be powered by a pusher 220x motor with a 6045 prop and I bet it would be fast and fly just fine. I just haven't tested it yet.





Flight Characteristics: It is a jet, but a forgiving one. With a 700g AUW and twin motors pushing up to 900g thrust each (over 2:1 thrust weight ratio), it will lift straight out of your hand like a prop plane. Just grab it on the inside of one of the wings and give it a good toss and off she goes. The plane is fairly agile with just the elevons, so no need for ailerons unless you just want to. I have yet to stall this thing, but I am sure it is possible. It slows down nicely and does high alpha moves fairly easily. Whatever you do, don't make it too nose heavy or it will lawndart! That killed the first two prototypes.



Place the motors all the way in the back if using a 2200 battery, and scoot them forward accordingly if you will be using a smaller battery. Remember, with this plane it is easier to move the battery forward than it is back.



While you can build this with the forward canopy/nose glued on and cut hatches, I would suggest that you just stick a couple of magnets on the back of the forward fuselage, and the main body, and have the whole thing removeable. I fill the nose with expanding foam, so that when it crashes, the front is breakaway. I haven't destroyed a nose yet!



Plans are located in the plan vault.

[Burkeomatic]

Build Instructions.

1. Get the base cut out. Once it is cut out, transfer and trace the patter in a mirror image to another piece of foam to make the other side.



Next tape up your two halves (try not to do a crappy job like i did and make it even). Then you want to glue it up and tape the other side. I used white gorilla glue, but anything will work.



Then after you did that, cut your scores and notched for the engine pods. The reason I waited until now to do those cuts is so that I dont accidentally make 2 left or right sides.


Then pick what you want to do for a spar. One 1/8 inch bamboo skewer and a couple popsicle sticks were enough to support the wings on the alpha version. You can also use a really long paintstick in the middle or you can do 2 smaller ones off to the sides at an angle.


These are your options. I typically do two angled about an inch behind the leading edge, and one across the back. If you want to keep it lighter, you could just do the one across the back. 







If you like, you can cut out the bottom of the wing for an aileron or flaps or spoiler control surface if you like. I don't because this is where i like to throw it from. Bevel your wing scores, i don't really do the 45 degree cut anymore. I just use an extra large bbq skewer. I go through with the pointy end then the fat end.




You can depaper the top if you want. I didnt for the alpha, but I am for this one. Leaving paper theoretically adds strength. Ive never had a defoamed upper wing with gorilla glue fail on me.



I like to tape the front of the wing where it folds so it wont crack when you fold it.




Continuing on... fold the wings over and weight them down, glueing them with white gorilla glue, it is seriously strong.

Fold your wing over and make sure it lines up. Weight it down with something that wont leave a mark.






Repeat with the rear stabs. You need to put some popsickle sticks back there to stiffen things up. This is what everything should look like when you are done. 




Next get your engine pod cut out, depaper it, and get it bent into shape.




Instead of cutting out the motor support, you can just wrap the bottom half in a sheet of depapered foam.





Dry fit the pod, it should go quite all the way down. Your motor will leave a mark. Then take your motor and roll it around to make a crease in the foam. The motors should be mounted all the way in the rear, where the motors are nearly even with the back of the fuselage. Also cut holes in the lower fuse for the motor wires to run through.







Put some glue around the lip of your engine and the foam where it will contact the pod, then glue your pod over top. Repeat for other side.

Flip the plane over and get your electronics hooked up. Make sure everything turns the right way. It isn't pictured but hook up your servos and drape them out of the back.





Next the turtledeck. Depaper one side. The rear fuse right next to the h stabs where the popsicle sticks are is important and you want that to be very solid. I used liberal amounts of gorilla glue as it expands and is strong. It is probably the best glue for this job. Alternatively, you could use copious amounts of hot glue. You also need to glue up to the leading edge of the wing. Let this dry completely!
Next we will shape the front. In a twisting motion pulling up and in gently twist/pull the bottom edge of the turtle deck even with the main fuselage and glue it up. A little overhang is ok. I used thick and quick and taped it up.




Depaper the upper fuselage canopy section and start forming it.

 


Start by folding the bottom together first, then the top.



Finish up the front section, mold your nose cone and glue it on. You'll probably need to sand each side flat. I've only had them come out perfect once.



It just slides on to the front. You can glue it on and cut hatches like I did on the prototype. On this one I just put magnets on the back of the upper fuselage and canopy part and the whole unit slides on and off. Magnets are best, as the whole thing just pops off on a nose impact. You can fill the nose with expanding foam and say goodbye to the dreaded witch's nose. 



Put your servos about right there.


Form you upper motor covers up and glue them on.



Then glue your vertical stabs on and boom! You have a mig 29!



Feel free to add ailerons, you don't need them. Might be neat to do flaps too. I figured you have 2 elevator servos, may as well use them!

Just grab it toward the inside of the wing and fling it like you are tossing a flying wing at about a 20 degree angle at 70% throttle. 

[Monte.C]

You make it sound so easy! Makes me want to build a jet, but everybody knows jets are dumb. (That's the sound of Burke's chain being rattled.) Kidding! I thought you were holding the Tease Me stick. Sweet project. 👍

[Burkeomatic]

May 5, 2022 16:16:08 GMT Monte.C said:

You make it sound so easy! Makes me want to build a jet, but everybody knows jets are dumb. (That's the sound of Burke's chain being rattled.) Kidding! I thought you were holding the Tease Me stick. Sweet project. 👍

Sad thing is, it will probably fly just as well on a 2206/2100kv motor. It will just sound like an electric weedeater. 

[Monte.C]

What are the general specs?

[Burkeomatic]

AUW is 700g, 30" wingspan, about 36" long I think?

[Monte.C]

👍

[Burkeomatic]

i'm putting my photos in. This embedding is a PITA when you have a huge build all at once.