Web log of the Quadrocopter-E prototype

Finally an idea for the supports: Drain pipe cut into slices, screwed to the arms inside the motors. How long this will last is questionable, but the spring effect is very good.

Weak points:

• The central metal plates do not have their holes at the same distance from the center. This means that the arms can only be reassembled with a different extension width from + (currently) to x configuration.
• Furthermore, this means that continuous arms cannot be used as the holes do not fit.
• There are no holes to rotate the board by 45 degrees (as an alternative to the arms) .
• A cover for the top level, i.e. the circuit board, is currently still missing.

Conclusion: 1) The support plates should be round and have uniform holes at 45 degree intervals ; the holes for the circuit board should also follow this pattern. 2) An additional round plate forms the upper end above the circuit board (roll bar and mounting platform for additional sensors or a camera). To save weight, a ring instead of a full disk is sufficient.

To switch from + to x configuration, a software adjustment/setting should actually be sufficient!

The engines are reassembled. Another flight attempt. The aircraft gets out of control and has to make an emergency landing. The same happens on the second attempt. Diagnosis: Right-hand and left-hand propellers have been swapped so that the torques can no longer be adjusted. Propellers are offset by one arm each . Now it works.

Weak points:

• Support screws are not under the arms, so the plates are all bent during hard landings. Screws would be better placed under the arms.
• Landing props are missing, but it is unclear what they should look like.
• Continuous arms (2 instead of 4) would improve stability.
• The battery should not rest on the bottom plate, but hang over it (Velcro!) and be secured with two additional Velcro straps.

Further flight tests. Two of the motors are clearly too warm and also turn with difficulty. Disassembly reveals: A spacer disk is pressing on the lower ball bearing due to burrs on the edge. In addition, the holes in the arm for the axles are slightly too narrow. Drill out...

First flight. After everything has been assembled, the pillared hall becomes a test flight area for a short time. Then the inner courtyard. So far everything seems to be working, it flies like a model helicopter - with the same instabilities.