Arducopter3D with SimonK reversible ESCs

This was the maiden flight of my 3D hacks to the Arducopter 2.9.1b code. So while my piloting sucked, I was pretty impressed that it actually worked!

The ESCs are Afro 30s with SimonK configured with COMP_PWM=1, MOTOR_BRAKE=1, BRAKE_SPEED=8 and of course RC_PULS_REVERSE=1 to allow reversing.

The props are actually two sets of carbon fiber props stacked on top of each other with one set upside down - another hack. This is far from ideal, but all I had on hand at the time. Normal props are far too inefficient in reverse and I actually don't have any I can flatten out (yet). I can't wait until 10" 3D props are common!

The code needed quite an overhaul to simply support negative throttle. On top of that, I added some delays when switching direction to make sure the motors stayed in sync when reversing direction. The final cherry was to have the acro mode self leveling mix switch the roll target to upside down when the throttle reversed. What you kind of see in the video is me just reversing thrust and letting the computer flip it over for the inverted hover.

Next up: learning how to fly and tune it!

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  • I finally got out for some more test flying! This time I tried 9x4.7" CF props - MUCH better. The 10's were likely too heavy for the 1400kv motors and I wouldn't tune quite right. These 9s seem to have more of a slowfly shape to them and sound better, even with 4 blades chopping the air. Now it seems to be flying great both right side up and up side down*. I'll upload the video from this session when I get it.


    *I seem to have a bug in the acro pitch auto-level code that strangely keeps the pitch axis working 'normal' when inverted. It actually makes it easier to fly, but it isn't right ;) 

  • Developer

    Interesting thing, saw such quad the other day and wondered when this will popup here :)

    Well done!

  • Will do - once I've put a few hours into flying it. 

  • Developer

    very nicely done!  You should post your code somewhere in case anyone wants to see it, even in case it's not super clean, the final result is impressive.

  • Fantastic work, excellent start, really looking forward to this becoming a viable option.

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