Simple V-Tail

I originally wasn't going to share this plane, but I like it's simplicity and versatility too much not to share. It's simple because it's just a triangle tube, wings, and the V tail fins are a single piece. It's versatile because you can have the motor either in the front or the back and you can have the V tail either up or down. However, I'm unsure if the prop will interfer with the air coming off of the tail too much to work. You may have to use a small prop if you make a pusher V tail plane.

The plane that I made seems to be under powered. But I think better, more effiecient wings would be a better solution. I have to admit, I hate the wings I put on this plane. I haven't learned how to make the fold over wings like the FT Baby Blender, or SpitFire. I wanted a flat surface for the wings to glue onto the fuselage properly so I went with a KF step. ... It really needs a bigger airfoil.

Another issue is that the fuselage isn't long enough. The nose is too short so I had to add nose weight for proper CG. I made mine 30" long, but it looks like I'll have to make two triangle tubes and glue them together (probably with small pieces of foam board glued inside of both tubes) if I want a longer fuselage.

Basically, I plan on making a "version 2" with a longer fuselage and wings that are more like glider wings. I also hope to make it a swappable. To make is a swappable, I plan on removing two of the sides of the tube for the length of the power pod. I know this will make a weak point where the triangle tube and power pod meet, but I plan on gluing the wings on at that point to stregthen it. I will share version 2, I just may not have time to work on it for a while, assuming I ever get around to building it.

On a personal note, last night was the first time I landed a plane within ten feet of me. It was a proud moment. It pretty much was the first time I landed a plane on purpose. And it was with this plane.

 Notice that the V tail is a single piece with a score cut down the middle and broken in half, leaving the paper on top. This makes it very easy to glue the V tail on and have it lined up properly. Also notice the corners of the triangle tube. When bringing the two sides together, the top corners just fold that way on their own. When gluing the triangle tube together, I glued both top corners at the same time and held the bottom corner flush, with the shorter side under the longer one. After the glue cooled, I went back and glued the bottom corner. This triangle tube is easier to make than a square tube, and should be stronger.

I also want to mention that I made the bottom of the tube a perfect 90 degrees. This makes for a much stronger butt joint. However, it sounds like 100 degrees is best for a V tail. In simple terms, the flatter the tail, the more elevator authority you have. The more vertical the tail, the more rudder authority. I figured that the added strength of the tube outweighed it having the best elevator to rudder ratio.

Another note is that you have to make an alteration to the Flite Test firewall. You have to cut two of the cornerrs off so you can properly tape it to the fuselage. I also want to mention that I don't like how wide the top of the fuselage is, but it has to be in order to fit the FT Firewall and to give the V tail it's 90 degree angle.

 I decided to mount the back two servos into the tube. To look better and for less drag. I probably should have done something similar with the aileron servos.

This is just a quick video to prove that it can fly. It's underpowered so I had to have full throttle the whole time.

 Plans:

This whole plane is straight lines and is pretty basic. Instead of drawing out the plans, I think giving you the measurements is enough.

Triangle Tube: 2 1/2" - 1/4" - 3 1/2" - 1/4" - 2 1/4" (Remove the two 1/4" strips. The foam board is actually less than 1/4" thick, but the little extra room makes it easier to fold the two sides together. When folding those sides, take your time, don't force it. The foam board needs to compress a little for it to fit together. Also make sure that the little shorter side is under the longer one. Making a butt joint.)

Wings: 20" x 8" with a 3" KF step. (Each wing. Total wingspan being 40") ((I strongely recommend making better wings than I did!))

V tail: 20" x 6" with a score cut down the middle to make the V shape. The control surfaces are 2", leaving 4" of fin. You have to remove some of the middle control surfaces so they don't hit each other. I just cut out what I thought looked the best.

Basic V-tail information:

When mixing the two servos for a V tail, it's basically the same mix as for a Delta wing, except you're mixing elevator and rudder together, not elevator and aileron.

When you input Up elevator on your Tx, the left fin moves in a down-left motion, directing the air down-left. The right fin moves in a down-right motion, directing the air down-right. The left and right forces cancel each other out, pushing the tail up. When you input Right on your rudder, a similar thing happens except it is the up and down forces that cancel each other out, pushing the tail to the left.

End:

I think the one thing to take away from this article/build is the triangle tube. Again, I recommend making better wings and feel free to make the V tail bigger, or smaller. I just did whatever.