I work for CJ Youngblood Ent, a remote control helicopter and quad-copter design company based out of Texas.  A few months ago we released the Stingray 500, a full collective-pitch quad-copter for the r/c industry.  There were a lot of good responses to the model, and a lot of people wanted to see a nitro version.  We have completed our single-motor internal combustion collective-pitch quad-copter prototype:  The MantaRay.

The MantaRay is a proof of concept, and is not necessarily intended to be produced in this exact configuration, however we feel this model is leaps and bounds ahead of the industry and will help pave the way for a lot of great technology in large-scale stable flight.

We hope you find this interesting and would love some feedback on interest.

E-mail me when people leave their comments –

You need to be a member of diydrones to add comments!

Join diydrones


  • Hi i was thinking of modifying my current stingray to nitro engine. May i know how did you modify the TG Multi to control the motor's valve? 

  • It's called a fuel clunk.  It weighs the fuel line to the bottom of the tank, in whichever orientation it is in, just like in helicopters.

    Some examples below: Fuel Clunks

  • how do you keep fuel flow whilst upside down?

  • Brilliant, now we're getting serious, as Henry Ford once quoted;

    If you think you can, or

    think you can't,

    Either way your right.

  • We did this for the same reason multi-rotor helis have a place already in the workplace.  Heavy lifting combined with with a more stable platform where the weight doesn't have to be centered under one rotor.  Also the flight times of a large internal combustion motor seem to be something everyone is after.

    You also use much smaller blades than a heli of the same size, so there are some safety perks.  The whole point was to prove the concept that a single motor internal combustion quad can sustain collective pitch flight, which it did.

    Now the model can be scaled in any direction.  The flight control is our TG-multi, the motor is an O.S. 105 pumped nitro motor on its second tank ever. JR propo radio equipment.

  • @John: +1

  • Pretty cool for 3D.

    BUT if your goal is endurance and efficiency, then why would you use 4 rotors when 1 rotor is far more efficient and has less failure modes. I am wondering, was this created because it sounded like a cool idea or was there mission or operational reasons for it, and what are those?

  • Once I saw the basics of the Stingray operation, the Manta Ray was the next obvious step.

    Vibration discussions aside, the control software of the of the Total G (credited to Curtis' dad BTW - go find the FliteTest video interview/demo), would not care if the rotational power source were a wheel of gerbils or zero point energy as long as the power density met the requirements for flight.

    Gary McC has it dead on - duration. A liter of liquid fuel will keep it in the air far longer than the equivalent size of a LiPo battery. Once the density/weight/volume equation of the battery exceeds fuel, that will change again.

    My guess is the target audience is something other than the hobby market.

    We have all been waiting, debating, thinking, sketching, experimenting, and planning for this.

    Youngblood et al just went out and did it. Bravo!


  • Developer

    I understand the drive to build something just for the experiment. But from a design and usability viewpoint I have to ask why?

    It has 4x and then some the complexity of a helicopter and all the disadvantages of a quad. The entire reason for multicopters becoming popular, was the dead simple design with some sticks in a cross and some motors at the ends. Easy to make and cheap to fix. That simplicity makes them worth it, regardless of bad aerodynamics and lousy efficiency. If you want premium mobility and efficiency, and can live with the added cost and complexity then you fly a helicopter. But if you just want a hover machine as simple and cheap as possible, you go the multi route.

    Sorry if I come of as a downer, but outside the "just for the kicks of it" I don't see any advantages with this design. A helicopter flies better and actually has less complexity, and a normal multicopter is MUCH simpler and robuster.

  • Curtis Youngblood is awesome and so is his hat!

This reply was deleted.