In this edition of our buyers guide series, we will discuss electronic speed controllers. Specifically, we will talk about how they work, what you should look for when purchasing one, and offer a few of our favorite options on the market. What does the ESC I choose affect? The — One of the first on the market to use the BB processor chip. The job of an ESC is relatively simple to understand — it controls the speed of the motor in response to commands from the flight controller. The faster the motor turns, the more thrust it generates, and the more speed you will get out of your miniquad. The way the ESC communicates with the motor can actually affect the amount of thrust that motor generates. In his bench tests on , QuadMcFly found that from the best ESC to the second worst on the market, there was actually a 20% variance in thrust produced from the same motor. Interestingly enough, this is pretty similar to the variance seen in testing different motor brands. This means you can gain just as much thrust performance from picking the right ESC as you can from picking the right motor. The way the ESC talks to the flight controller matters as well. All of the ESCs on this list talk using Oneshot125, a communications protocol that ensures a reasonably low-latency communications link between the two devices. However, ESCs with faster processor chips are technically capable of talking to the flight controller more often. This is currently the bleeding edge of performance gains, but ultimately it will mean a smoother flying miniquad once they are realized. Given that ESCs have just as much of an affect on thrust performance as motors, and that they have a huge effect on how smooth your miniquad flies, we believe that ESCs are the single most important component you can buy for your miniquad. Do not cheap out. There is no real reason to — there are great ESCs on the market for every price point — see our recommended pick below. What makes a good ESC? Pictured is a 4-in-1 variety of the line of ESCs. This ESC is meant to be mounted under the flight controller. This is measured in amps. The compromise with higher ratings is generally larger size and more weight. This is the amount of power an ESC can handle for short periods of time. This is a convenient rating for miniquads because often time you will be hovering at very low power settings with spurts of high power usage. All ESCs on this list will support 3S and 4S batteries, the most common used in miniquads. If you want to build a monster, you may be interested in 6S support. The most popular form factor for an ESC is that of a small chip that gets mounted to the arm of your quadcopter. This type of ESC is easy to work on and replace but does affect the looks and aerodynamics of your quadcopter. Recently, with smaller quadcopters becoming all the rage, 4-in-1 ESCs that mount underneath the flight controller in the main body of the quadcopter have become very popular. These are lighter and easier to wire, but carry the risk that a failure of a single ESC could warrant replacement of the entire board. These can be individually replaced if any ESC fails. The best of both worlds for those needing a 4-in-1! As miniquads get lighter, the arms get thinner and shorter and the space for the ESC gets smaller in the process. Also, a smaller ESC generally looks much nicer. Like motors, these weights are multiplied by four and generally bring the weight away from the center of mass of the miniquad. You want your ESC as light as you can get it. This is not even a question — DSHOT is the best new miniquad technology of 2016 and any ESC you consider purchasing should support it. This should appear in the specs for the ESC when you are buying them. Read our for more details. It offers advanced features like telemetry, configurable LEDs, current sensing and more. Read for more details. They are the ESC to have if you use the KISS flight controller. We strongly recommend you do not buy a SimonK ESC if you are a beginner. For the purposes of building a miniquad, the optimal ESC is one that has no wires or wires only on the power and ground side. The optimal way to build a miniquad is to solder the motor wires directly to the ESC outputs. Hardware PWM will make your quad noticeably quieter and slightly more efficient. It also affords more fine control, although we honestly are not sure humans can take advantage of this. Here are the technical details of this feature:Motor speed control is accomplished by raising or lowering the voltage sent to the motor. Up until recently, this switching was controlled entirely by the microchip that controls the ESC. KISS changed that on their models by adding a separate driver chip that was responsible solely for producing the switching signal. We update this list regularly and our pick will always be the best combination of price, features and performance. Realistically, you do not need to know all the above information to pick a miniquad racer ESC. This is done to make comparisons easier. References — Special thanks to QuadMcFly for his excellent tests and research. I have learned a ton from his informative posts. Like many of our articles, many of the links above are affiliate links. We urge you to shop around, but if you do decide to buy from the vendors above, we would really appreciate it. EMax Lightning removed because of recall.
