Sunday, August 30, 2009

First Flight - Manual

Status before the first flight:

First flight was supposed to be without any payload for reduced weight and increased maneuverability, but I misjudged the extra weight of the heavier wire used because of the motor, so the plane became nose heavy and the fort three attempts at flight looked like this:

video

After adding the payload (namely the G1), the center of gravity was restored and the plane took off. But it started immediately turn to the right (miss adjusted rudder) and here I made my first piloting error. In the attempt to level the plane with the elevator I accidentally also moved the aileron control (located on the same controling lever), causing the plane to bank and crash:

video

Resulting in this:


Things to be considered before the next flight:
  • readjust the rudder for the extension
  • increase the speed/strength of the plane launch/throw
  • increase tail weight or decrease nose weight
  • stronger propeller attachment (came lose after every crash)
  • move or remove aileron control pending more experience

Saturday, August 29, 2009

Assembly and Modifications

So, the fun part began ...

First of the fabrication of motor mount for stronger outrunner brushless motor, to compensate for the intended extra weight.

Next the carving of the airframe to create the extra room for the motor mount, stronger wires and the payload area.

Following by the modification of the wings with the aileron mod, which consisted of mesuring, cutting out the aileron plates and carving out the servo space.

After all the cutting and carving came the gluing phase. Pretty straight forward, airframe, elevator, rudder, payload door. Some deprom foam was added at the cut out edges of the payload door for a tighter fit, since cutting them out weakened the airframe. Also, the rudded was extended to give it more authority to cope with the increased weight and stronger motor.

On the wings, the aileron plates were attached with enforced paper strips, connected with a steal wire to the servo motor and the connecting control wire glued inside the wing withing the hole for the reinforcement tube.

After it all set, came the carving of a tight fitting space for the G1 and the motor regulator. Once it all fit together, were the payload doors equipped with a strap made from duct tape and secured with Velcro.

Obligatory electronics test and color coding of the wires. Interesting fact: 250W old computer power supply did not produce enough current to start the motor, so the test was servo mechanism only and as a result motor connections were color miscoded.

After weiring it all together and performing another test with a charged battery, the polarity of the motor was corrected and with the 803g without payload and 1047g with was ready to fly.

No markings or tail number as of yet due to a writers block in the naming department.

Saturday, August 22, 2009

Plastic Wrap Test

Interest of the day was Center of Gravity (CG) or the mass center of the aircraft at which the entire weight is centered.

Since the plan is to "tweak" the airframe a bit to carry additional weight I wasn't ready yet to glue it together as per assembly instructions and decided instead to provisionally wrap it in plastic wrap for sandwiches, to hold it together for a short test flight.

Before that, was fully equip with all the heaviest components:
  • battery pack
  • motor
  • servos & receiver (located on the outside)
  • motor controller
  • three packs of £ coins*
* simulating tested position and weight of G1 (to be carved out after successfully testing the center of gravity)

With about 760g it was ready for a series of short flights (no RC control, the battery has yet to be charged).

The most "successful" was the second arrangement with the battery at the back of carved out space and the simulated G1 in the fuselage, closes to the beginning of the wings.

video

In fact it was a bit too successful, since it kept flying after the desired couple of meters.

P.S. Please excuse my brothers laughter at the end, he only meant well.

Monday, August 17, 2009

Flying Material

Acquired some flying material today:

Admittedly there were few ideas for own design and fabrication, but after a quick reality check was decided that acquiring some real world flying experience would probably be better. So the following shopping list was devised ...

MULTIPLEX EasyStar airframe:
  • prefabricated (will design next one)
  • made from Elapor (much needed easy fix)
  • recommended for beginners
  • large fan base (community mods and designs)
Also a 5 channel 2.4 GHz radio transmitter and receiver:
  • ch 1. - throttle
  • ch 2. - rudder
  • ch 3. - elevator
  • ch 4. - aileron (will be added later)
  • ch 5. - autopilot manual override
And a few other little things like battery pack, servos, glue, ...

Thursday, August 13, 2009

Things to Learn

Short brake later, we're back.

With some time to think it was decided that it might be a good idea to brush up on the basics first.

So, this is going to be done next: a GPS receiver for FlightGear.

Point of this "exercise" will be to gain some experience in Android, specially with background services.

I mean, it would be kind of bad if an incoming call would make the plane crash. Definitely not a condition to make this project successful!