The Swarm man carrying multi-rotor airborne flight testing montage. 54 counter-rotation propellers, six grouped control channels with KK2.15 stabilization. Take off weight 148kg, max lift, approx. 164kg. Endurance10 minutes. Power approx. 22KW.

Just a bit of fun for my self, never intended for making a significant journey or flying much above head height. Approx cost £6000.

Props at 18 in were the largest I could find with contra rotating pitches and so defines much of the layout. Also the fine pitch allows them to turn at high speed which reduces motor weight for a given power. Motor KV chosen to work with 4 cell batteries with 20% or so control margin. This low margin maximises the ESC efficiency, higher margin results in higher circulating current losses in the ESC and motor, reducing endurance.

54 chosen as this fits the hexagonal close pack layout. 6 more could be added in the centre. 18 in props at 5000 rpm though hazardous, are still much less so than 6, 5 ft ones. Where could you get a low power 5ft prop from weighing less than 1Kg with opposite pitches? The 54 gives good redundancy as mechanical and power electronic systems are the main failure areas. I have had one ESC randomly fail already. Controls could be made fully redundant (9 x KK2.15s) so only the control sticks (and pilot) are single failure points. Redundancy increases the likely hood of failure but reduces the consequences.

Props are standard RC aircraft types used at a relatively low fraction of their thrust/rpm capability. So should be reliable though needlessly heavy. Being inline with my head the polycarbonate dome is for protection. The polythene bubble balloons up catching some ground effect pressure rise contributing to lift. It also doubles as a rain shelter…

Batteries, ESC and motor are close together to minimise wiring weight which is significant because of the high current 30A. Also the battery damps vibration. Individual batteries does mean some may run down a little quicker than others. The front and rear groups are used for pitching, a more common manoeuvre so far than roll.

No one has spotted the biggest flaw! That is the large number of props running at high speed means the net torque reactions are relatively low, so the craft has little yaw authority. So it probably needs a tail rotor for spot turns.

35 COMMENTS

  1. You know what this reminds me of? It reminds me of those old video clips where people tried to fly those old weird types of airplanes. You could sort of tell it were going somewhere, and that it was going to be HUGE. But it's just not quite there yet. THAT'S what it reminds me of.Drones are certainly going somewhere. This is only the beginning. Just wait and see. ;-D

  2. Paul, would it be possible to use the electronics and gps system found in a DJI Phantom drone or similar to make this a breeze to operate.
    You already know it works, it just needs the stability provided by the electronics and you could fly it with an Ipad

  3. you would think with dji inventing the dji phantom drones with built in barometer,obsticle avoidance,self leveling,ect ect… dji phantomcould of built a full scale with big ol 15 inch props and big ol brushless motors….cool video…glad someones working on it.

  4. although a cool project, some people have more money then sence in this country. that money could have gone to charity or the homeless.

  5. You hear him scream like a girl and this is because he does not consider the device safe enough to go to far from the ground and was afraid of crashing and dying.

  6. So I get the redundancy of multiple rotors. What about a rotor failing and slinging pieces into other rotors setting off a chain reaction?

  7. Wasn't this the one that had the video of it being tested in a driveway and crashing a while back? I've never been able to find a mirror of that video 🙁

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