P-Trainer V1

August 18, 2014|APlane

This is a Scratch Built Plane I designed to teach my Grandpa how to fly.

PT-1 Specs:

WIngspan: 48"

Length: 34"

Motor: Turnigy Park 480 850kv w/ 10x4.7 prop.

ESC: Turnigy 30A Plush

Reciever: OrangeRX RX3X

Servos: (4) Turnigy 9018 Metal Geared

Battery: 1800mAh 3S LiPo

Flight Time: 7-8 Min/Battery

Weight: 900g

Design

After showing my Grandfather my scratch built planes, he asked me If I would build him one. He had previously lost a "DELTA RAY" in a strong wind. (It basically flew away on beginner mode and we never found it.) I of course said yes because I loved building these planes. I knew it would be more of a challenge to make a plane that was easy to fly by a beginner. All of my current scratch builds were certainly not worthy of being "Trainers." So I set out to find the best qualities for a trainer plane.

I knew it needed dihedral so it would self right itself. I had never made a dihedral wing, and was'nt confident enough in my skills to do so. So, I went with Polyhedral. I also wanted it to be easy to repair after a crash, so a simple design would work best.

Here are the drawings I came up with:

Build

I started out with a standard piece of Dollar Tree Foamboard. I drew out the fuselage side plates and bottom plate. Each side is 3 inches wide, which equates to a square fuselage tube 3"x3". I used the whole length of foamboard, which makes the plane 30 inches long. The end of the tail tapers up to the top.

I cut out the fuselage and the Stabilizers.

Next, I folded up the 2 side plates and Hot Glued it to the bottom plate.

I attached a top plate to the rear of the fuselage and glued on the stabilizers. The Horizontal stabilizer has a movable elevator 2 inches wide. The rudder is also 2 inches wide.

Next, I glued in the 2 inch thick firewall made of green foamboard.

I extended the fuselage down 2 inches to mount the landing gear directly below the motor. This will keep the plane from flipping on its nose when landing in grass.

Now it was time for the wing. I began with a piece of foamboard 30" by 10" as the first layer. I added a second layer and cut out spots for the wooden spars. Then I glued on the top layer. Each layer was smaller than the previous so it makes a KFm-3 Airfoil. I cut out the ailerons and added on the wingtips.

I added on the stripes, and the landing gear.

In the battery compartment, I put in velcro and foam to hold in the battery.

I got all the electronics in the mail, so it was time to finish off the plane.

I made the motor mount out of 2 popsicle stick, that I cut and double layered, and glued to the firewall. Then I screwed in the Park 480 motor and zip-tied on the 30A ESC.

I'm using a reciever with a built in gyro to help with any wind. I put in the fuselage, then added the 4 servos for the elevator, rudder, and ailerons.

I attached the pushrods to the servos, and to the credit card control horns, then put in the 2 wooden sticks to rap the rubber bands around that hold the wing on.

The first flight was on a windy day. But the plane was able to fly very well. I ended up increasing the size of the Elevator and Ailerons. Overall, It flew great! Now, hopefully it was easy enough for my Grandpa to fly!

I took it to my Grandpa's house, and I let him fly it. He was not used to it being so responsive, so he had trouble flying. We used a "Buddy Box" setup, so I could always override him and take back control of the plane.

One day, when I was about to let him fly, I noticed the elevator servo was fluttering up and down before takeoff. I decited to switch it out with a new one. After I removed the servo, I had ripped out a lot of the foam, so I had to glue in some popsicle sticks to support the new servo. This had moved the center of gravity back, and when I went to fly it, it almost crashed. Luckily, I was able to land it safely. I glued in some AA Batteries to the nose as counter weight. It flew alright, but after a while, the ailerons did'nt seem to have the proper effect, and the plane crashed.

The plane was totaled, but the electronics were fine. So, I started plans for the P-Trainer V2.