I was invited by OttawaDrones, a group of FPV flyers and drone designers, to do a short presentation about our dynamometer. My objective was to help them make quads and drones that fly longer and are more powerful.

I decided to do an introduction to motor and propeller theory, efficiency, and testing. I wanted to give the audience an intuitive understanding of the equations, so that they can design better, faster and more efficient quads. I tried to make this talk different and interesting by talking about the theory while giving concrete examples and showing real test results done with our tool.

Here is an overview of the talk:

  • Problem: Why test motors and propellers?
  • Stalled motor as a resistor
  • Stalled motor as an electro-magnet
  • Moving motor and back EMF
  • Mechanical power and heat losses
  • Motor timing
  • Propeller definition and parameters affecting efficiency
  • Motor and propeller selection
  • Questions

We got to demo our tool after, and we talked with really cool people! I really recommend going to one of their meetup if you have a chance. They have great projects, and you can do some indoor FPV flying in winter!

I am planning do a series of tutorials discussing more in depth each topic mentioned in the video, so your feedback and questions are very appreciated. I will do my best to answer!

Views: 978

Comment by Darius Jack on December 17, 2015 at 3:52pm

Thank you Charles,

excellent presentation.

My idea is to develop hybrid small drone powered by gas motor

powering electric motors via direct drive generator.

I would like to calculate efficiency of such hybrid thrust generation.

Looking for lightweight gas motor + neodymium 3-phase generater all-in-one

generator to power up  electric motors via controller and battery as back-up in case of emergency.

I am looking for  fuel consumption/ energy generated efficiency chart/s for

a number of 230v power generators.

Developing Toyota Hybrid Car to fly ;)

Could you help me ?



Comment by Charles Blouin on December 17, 2015 at 5:22pm

Thanks! BTW, here is the link to the video, I think it does not always work for mobile.

@Darius We are pretty busy with the recent launch of the dyno, but you might be interested by the work of my colleague when I was doing my master's. He built an hybrid motor. The idea was to use it on a blimp. The advantage is that fuel has a much higher energy density, so it can be used to charge the batteries used to power the electronics. Using this system, the vehicle could travel very long distances, or stay in the air for many days.  You can look at his thesis here. There are a few pictures, and a lot of test results.

Comment by Darius Jack on December 18, 2015 at 8:39am


thank you so much for your kind reply.

I have downloaded dissetation referenced by you.

Highly professional R&D. It may take me days to fully understand some chapters.

Compliments go to your friend.

His hybrid powered blimp project resembles me exactly novels by Jules Verne,

Maître du Monde, 1904

 Robur le conquerant, 1886

and Master of the World video on Youtube


I would like to know ( calculations) if gas powered generator from ebay (230V 1000W power generated) can lift itself if airframe, motors propellers are attached ( AC > DC inverter, controller, all included)

or how to calculate net lift force in case of hybrid drone (airframe, hybrid generator, propellers, fuel tank - all inclusive)

Could you let me know your opinion ?


Comment by Darius Jack on December 18, 2015 at 8:45am
Comment by Charles Blouin on December 18, 2015 at 1:58pm

Hi Darius,

Without more specific numbers, it is very difficult to help you. Have you tried to do some calculations? Are you stuck somewhere? 


You need to be a member of DIY Drones to add comments!

Join DIY Drones

© 2019   Created by Chris Anderson.   Powered by

Badges  |  Report an Issue  |  Terms of Service