Well this is the first time I have evidence of the H single motor failure mode.
Notice the opposite prop???
Notice the opposite prop???
5 motor operation
- Thread starter Chilcotin
- Start date
Trent from Yuneec had mentioned in a video back in January (or February) that when the Typhoon H is running on 5 motors, the 5 motor will spin the prop 3 times clockwise, then 3 times counter clockwise. There are still some people (mostly on the RCGroups) who believe this to be fiction, however, so far the videos of the Typhoon-H running on 5 motors always show the 5th motor (the one opposite the motor not working) to be spinning in a start/stop fashion... as in this video and others. So it seems very likely that it could very well be the case as per Trent's explanation.
Yes that is the way it looks. I was skeptical to be honest. Just seemed to me that it would be too hard on the prop and motor. I am glad it works as they described way back. Love it
Yuneec are obviously very innovative. I am impressed as I said before.
Makes sense to reverse speeds for that level of stability considering the weight of the boom down changes the CG quite a bit.
Running 5 motors on a hexa typically accelerates in yaw once you lose a motor to the point of uncontrollably (maybe "stable" visually, but uncontrollable). Most control systems can't keep up and will eventually flip since the thrust symmetry is off, even if you turn the opposite motor off (as he post later--it's lifts, but is very unstable). And if the copter is unbalanced (and no proper integrator in the control loop) it will flip in due time (starts spinning and arcs to a flip). Hence reversing the motors can "fix" that symmetry problem for a limited time.
Problem is all that reversing better have good voltage management (from the incredible spikes created) or that battery's not going to last long as well as the electronics will get fried eventually. Used simonk reverse mode here and it either kills my battery or generates a lot of heat.
That's why 8 rotors are the way to go--flying like a quad on 4, etc... symmetry is held in check.
Running 5 motors on a hexa typically accelerates in yaw once you lose a motor to the point of uncontrollably (maybe "stable" visually, but uncontrollable). Most control systems can't keep up and will eventually flip since the thrust symmetry is off, even if you turn the opposite motor off (as he post later--it's lifts, but is very unstable). And if the copter is unbalanced (and no proper integrator in the control loop) it will flip in due time (starts spinning and arcs to a flip). Hence reversing the motors can "fix" that symmetry problem for a limited time.
Problem is all that reversing better have good voltage management (from the incredible spikes created) or that battery's not going to last long as well as the electronics will get fried eventually. Used simonk reverse mode here and it either kills my battery or generates a lot of heat.
That's why 8 rotors are the way to go--flying like a quad on 4, etc... symmetry is held in check.
I don't think its actually reversing.... I think that's an optical illusion of the motor spinning up and slowing down rapidly as to make it look like its changing rotation. The motor controller would have to be capable of reversing polarity (something that would need to be investigated on the "H"). I'm not sure Yuneec would have setup that special of a motor controller to achieve this because this unit is not intended for inverted flight. You can reverse the polarity of the motor by reversing the leads. But reversing polarity of the motor controller would be a lot different... Not to mention lots of heat generating on the controller. Another issue is the blades are very inefficient running in reverse if they are not designed for it. The curvature of the blades is designed for single direction use. If that blade was actually reversing I would expect to see much more bouncing around and rotation. Decoupling one motors direction quickly would pivot the drone and would cause it to dip while the other motors would fight to try to keep it stabilized...
A simple tachometer would tell you if it's actually reversing... I might be wrong but something tells me that Yuneec did not spend the $$ to install a reversing motor controller (a six channel reversing controller...)
A simple tachometer would tell you if it's actually reversing... I might be wrong but something tells me that Yuneec did not spend the $$ to install a reversing motor controller (a six channel reversing controller...)
