Short-Tail Tough-Tilt Tricopter (or Dragonfly)

megabotz

TWO DOLLARS!
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I really like tricopters. The thing that jumped out at me in the design is that the tail is always going to be heavier than the other arms because of the tilt mechanism. Also, the yaw is far more responsive out of the box than pitch & roll. This is a classic lever problem for all you physics buffs out there.

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If you are putting a heavy camera up front, the CG being pulled back by the tail is to your advantage but if you are like me & are building something you wont feel bad about crashing, you aren't ready for cameras. Like myself, your design intent may require that the CG is as close to the middle without using the battery as counter-balance. You gotta admit that the battery sticking way out in front on the build video looked a little silly, right?

The battery is super heavy compared to the servo/tough-tilt but the length of the boom is what gives that tiny weight such a mechanical advantage. Think of prying a heavy rock out of the ground with a shovel. The CG is the fulcrum.

So I shortened the tail! As a dragonfly, it looks much cooler. The tail is now about 6.6" long & it flies. I was a smidge worried that short tail would decrease the lift on the tail relative to the front & cause the tricopter to pitch backwards naturally but this doesn't seem to be the case.

I would be interested in seeing if others have a good experience with a short tail (stinger?).

megabotz
 

Montiey

Master Tinkerer
Interesting, definitely have not seen this before. I wonder if moving the motors is any better than adding counter balance; Camera, battery, etc.
You'll still have to have slightly different PIDs, anyway.