Towing Our Homemade Creation

[BlockerAviation]

Pilot Blocker built from scratch a... I'm not sure what it is. We call it the Dragonfly.

Decked out with LEDs, an FPV camera, and all the ambition in Pilot Blocker's being. However, it took a few design tweaks over the months to get it just right. The maiden flight was earlier in the spring, and ended abruptly after going head on with a fence (we flew in a nearby baseball park). The camera on the bottom rotated, and was the beginning inspiration for the build. However it was never used during flight.

Some time later, fitted with a new wing for stabilization, and a redone tail, it flew rather well. However there was the issue of power from the motor--or lack of it. At full throttle, it needed a perfect drop in the ground to get the air under the wings as it needed to get in the air. Subsequently, it hardly had the power to remain in the air.

But after the final tweak to the angle of the motor, everything was in place--except getting off the ground. But we had an idea for that...

I apologize for the shaky camera, we have no better equipment. Just don't watch in VR and you should be fine.
We used a long piece of kite string that was tied to a key ring on each end. One key ring attached to the car, and the other end hooked onto a hook on the belly of the plane. When the car slows down enough, the momentum of the plane continues, and the key ring on it slides off because there is no lock. This is when the pilot takes control of the plane and flies it under its own power.

We have future plans to build a much larger variant, allowing for more of our bad ideas. Let us know what you think!

 

[BATTLEAXE]

This is cool, I wanna try this. I was thinking of using rocket engines for take off but this has some appeal too. Cool Project

 

[quorneng]

One advantage of electric is that is can be throttled pretty efficiently, actually better than it might be thought as although the motor is slightly less efficient at part throttle the prop tends to be more so. LiPo generally can provide a lot of power for short periods (10 seconds) as can brushless motors for similar short periods.
What does all this mean? It means you can install much more power than you need to fly for very little penalty if it is done appropriately.
Of course it helps is the air frame is as light as possible to allow as big a battery as is practical and also that air frame is aerodynamically efficient.
The prop size and pitch has to be carefully chosen and tested to both absorb the required maximum power and also to match the sort of speeds the plane flies best at. Likely quite a large diameter and fine pine pitch for the size & weight of motor.

My most extreme example of this principle has a full power (40 A) that is some 12 times that required to for minimum straight and level flight (3.3 A).

With that sort of excess power a take off is no problem (even just sliding on the grass) and the full power climb is vertical.
Just cruising is has an endurance of nearly 45 minutes.
Full power is not often used, nor is it needed for more than a few seconds, both to be kind to the LiPo and to avoid overheating the motor and ESC.
It uses a 3000 mAh 3s LiPo and a 1050 kV 55 g motor with a 10x3.8 "e" prop.
It works for me!