This is the crazy project that kept us busy lately at Quaternium: a hybrid electric+gas multirotor with range extender, inspired by Hybrid cars, such as BMWi3.

Our goal is to overcome the endurance limitations of an electric multicopter, while keeping the multirotor platform we are so enthusiastic about. This VTOL UAV has 2.5 hr estimated flight time with payload, and around 4 hours endurance otherwise.

These are the product specs:



20.0 KG


11.3 KG


7.0 KG


1.4 HR


2.7 HR


80 KM/HR


1350 MM

Why are we working on this?

As you all know, the drone market is only starting. We believe there will be many more  industrial applications emerging soon. With this new project, we seek to go beyond current technology limits and explore new possibilities of application.


What do you think about it? I’d love to hear your comments on this!




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  • Many commentators have the impulsion to cry fowl when they see a duck fly. The duck doesn't care what you call it and just flies because it can. ;-)

    Hybrids are about "de-coupling". In this case de-coupling the load from the energy source has both benefits and disadvantages. Advantages are like common quad copter type airframe and flight control can be used and performance can be improved by using higher energy density fuel. The only real drawbacks is the efficiency of the drive train to include a combustion engine into an electric driven quad and in comparison to a heli the reduced rotor size. Provided the losses can be kept to a minimum, by using light weight  engine and high efficiency generator components, it's not different to a fuel powered variable pitch quad, or similar gas heli. Provided the expended energy for flight is less than the generated energy the thing will fly until it runs out of fuel.

    As Rob puts it the numbers aren't that bad.

  • I don't understand the negativity in the comments here.  It's obviously a work-in-progress for the guys and has some considerable potential - leaving aside the comparisons with traditional helis etc.

    I think it's fabulous that you share these steps with us all Jose!  Well done on getting it flying and all the best for the endurance demo testing!  

  • So le tme get this straight, you've only done TWO flights and the LONGEST of which is minutes, how on earth can you claim 2+ hours then, and how does the media not see this ?

  • Moderator

    If there is a backup battery capable of carrying the load then the copter would probably survive an urgent RTL or LAND command.. If no battery then it will have about the same flight time as the average house brick. As its described as a hybrid then it should have a battery! 

  • Its good to see more people working on this problem. What kind of impact resistance does the fuel tank have? How long could the vehicle stay aloft if the motor failed?

  • Moderator

    The Genesys is a low power device not intended to use the entire power from the motor to convert to electricity, it was only supplying a few amps at most.. 

    If you apply any alternator to a motor it will generate AC voltage and this can be rectified easily to provide a DC source for your ESC. it does not need to be heavy, 4 x  60amp diodes works well. The trick is to get the correct size alternator to match the power and speed from the motor. its not about volts its about power. 

  • but then you need to convert 40 VAC or so to DC Voltage, that's another big weighty unit? is there a way around it?

  • This is great work.

  • Larger Custom Generators 

    Over a certain wattage size, we build Pancake Alternators. They are very efficient, simple, reliable (only one moving part, a ball bearing) and powerful for their size and weight. We design and fabricate these to the customers' specific engine, RPM, wattage and regulated voltage(s) requirements. We have built these from 30 watts to 1000 watts. They utilize Neodymium magnets for high energy densities.

    Some examples are:

    This is a 150W Generator mounted on a 3W-150® engine.
    This is a 300W Generator mounted on a 3W-100® engine.
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