Electronic Speed Controller


Under construction


This section is still baking.

An electronic speed controller (ESC) is one of four primary components in your power train. The ESC receives the batter current and signala from the throttle and drives the motor at the desired speed. It should have built in safety features and output telemetry to whatever readout you’re using to monitor your system. You don’t need to know how it works, but you should know:

  • All battery current passes through the ESC on the way to the motor.

  • ESCs must be rated for your designed current (amps)–what the motor will draw. They get hot. They can flame out and melt down.

  • You should design in some amperage headroom. If the you expect to draw 150 amps continuous, it would be wise to choose an ESC that’s rated for 200 continuous and 240 burst.

  • Choose an ESC can with built-in safety features; for example, automatic shutdown if battery voltage gets to low or temperature get to hot.

  • $$$ usually = quality. Quality = safety and performance.

  • Choose an ESC that provides adequate telemetry data: (RPM, current, remaining battery capacity, etc.)

Choosing an ESC


Current Rating : There are 2 current ratings to an ESC: continuous and burst.



  • If possible, place the ESC in a cooling airstream.

  • Wire inductance will kill ESC mosfets and may even blow the capacitors. Try to keep battery wires as short as practical and less than 12”. To mitigate this problem for longer wire scenarios, install an inline capacitor.


  • Choose a gauge that can easily handle the max amperage. See TBD.

  • Choose a wire type. Silicone wire is more flexible, heat resistant, and lighter than PVC, but it is also more expensive. Compare.

  • Keep the wires as short as possible.

  • Twist the wires in a spiral fashion from the ESC to the motor.

  • Connectors: TBD

List of ESCs

For now, refer to the list the Working build database.



These throttle and ESC work in tandem: the throttle controls ESC which in turn controls the motor, and the ESC sends telemetry back to digital display (often built in to the throttle). ESCs also often have throttle limits so that amperage can’t exceed the specified amount regardless of your throttle inputs during flight.

Throttle-power disconnect

Vendor examples

Reading telemetry data


Worthwhile reads

Notes, todo, not reviewed

INFO: https://forum.hanggliding.org/viewtopic.php?t=35303

Lipo batteries may ignite if mistreated. Mistreated means; overcharged, overdischarged, badly damaged. These batteries must never be allowed to drop below 2.9v per cell. If this happens, there is the fire risk if high current is still being pulled through it, and a battery overdischarged in this way will never take a full charge again, and may visibly ‘swell’. Therefore it’s critical when using lipo batteries to use a speed control that has an automatic lipo cutoff, ideally one which you can set. When I have the option, I always set my lipo cutoff to 3.1v per cell. (so when a 2s (2 cell) 7.4v battery reaches 6.2v, the ESC stops the power to prevent battery damage).



Joe Stapleton Ben Rogers Geiger MC300 will be excellent but a bit overkill for an e-help. Everything cheap and anything designed for rc models will burn at some point as they have no hardware protection. I build my own VESC FOC controllers now but that is a bit involved. If you use a trapezoidal controller rather than FOC/4Quadrant then the much simplified lower frequency switching reduces the chances of burning. I think some people have even used the super cheapo Flier controllers that are made by Freerchobby (rebadged FRC) and also rebadged by Alien in the UK.


I used to recommend the yongitech VESC hardware available from apiexpress/makerx/flipsky/freerchobby but I literally had one turn to plasma two weeks ago, albeit this is the first failure I’ve had like this. The specs (max voltage and continuous current) are usually constructed from the capacitor and mosfet datasheets the manufacturer used. This may lead to accurate max voltage (you must still allow a margin as inductive spikes from the motor will be greater than the battery voltage) but the current specs will be totally wrong and massively overstated. Personally I would de-rate any of the cheaper ESC to a max of 50% of their continuous current rating. Pay zero attention to any peak current rating it is meaningless.


All you need is a standard throttle or cameleon 2/3 and connect it to a linear potentiometer. a tension spring and a return spring depending on how the handling should be.