Is there any reason why one cannot add four pushers to a quad using just four escs to control all the motors?
I know that there would be no redundancy with that configuration, but there is an advantage related to lifting capacity...Anybody any experience with this?
Best DP.
Replies
Impossible (see following note).
But, can you split a control wire to control two ESCs (each controls it's own motor) so the Pixhawk could control 16 rotors (eight sets of 2 pairs) or 8 rotors (4 sets of pairs) only using a quad setup?
Note: An ESC is constantly sensing the advance of the brushless motor in relationship to it's magnets. That's the magic of brushless. Before there was a mechanical interface that did that job (the brush). The timing of when to switch from one magnet set to another (without a mechanical brush) determines if the ESC is going to rotate or just vibrate madly back and forth randomly. Since the load on any two "identical" rotors is always different, one will end up quivering ... and poof ... there goes the ESC.
The devil is in the details. Google to get other experences.
besides sync issues and twice the chance of burning out an esc running two motors in opposite directions and not gaining any real benefit of lift because of diminishing returns and eating up your lipos twice as fast I'd say no. That and LOTS of people have tried and this and they all pretty much come to the same conclusion. it's just not efficient. The thing about multirotors these days is they have been around for years now and every possible configuration has been tried many times and only the ones that "work" are still with us. Everyone likes to think they have "new" ideas and that may have true years ago, but these days most of what we see now is improvements on tried and true and not "theories", Look at helicopters. Coaxial are pretty much "toys" and all serious copters are single blade. My true X8 is not nearly as efficient as my single blade quads and hexes and the only real advantage IS redundancy not lifting. On a true X8 you lose an esc or motor and pretty much nothing happens. On a coaxial you lose an ESC and you lose 2 motors and down it comes.
Correct, but actually because one rotor is upside down and spinning the opposite ship-wise direction, both are actually spinning the same direction relative to the motor.