Site Logo



Specialist in Multirotor Tech & FPV Equipment

We ship worldwide - Same day shipping on all orders placed before 4pm - FREE delivery on UK orders over £99 <1kg*

Product Not Available - please see the DYS BL20A for an alternative product.

Afro speed controllers are the ultimate multirotor ESCs. Unlike conventional RC ESCs, these were developed from the ground up for specifically multirotor use. They boast high efficiency, all N-channel MOSFET design, jitter-free hardware PWM input, and exceptionally smooth power response. Not only is the hardware excellent, multirotor specific SimonK firmware comes preloaded! No need to reflash. They are also MikroKopter I2C compatible. A DIY port is available under the shrink wrap which allows using the ESC with MikroKopter hardware. Finally for added convenience the Afro USB flashing tool can be used via the PWM signal lead for future software updates, eliminating complicated flashing jigs or the need to cut open the heat shrink.

  • Continuous current: 20A
  • Input Voltage: 2-4s Lipoly
  • BEC: 0.5A Linear
  • Input Freq: 1KHz
  • Firmware: afro_nfet.hex
  • Discharge wire/plugs: 16AWG/Male 3.5mm
  • Motor wire/plugs: 16AWG/Female 3.5mm
  • Weight: 23g (Included wire, plug, heat shrink)
  • Size: 45 x 25.7 x 10.5mm 

What you need to know about ESCs: ESCs or Electronic Speed Controllers act as the messenger between your flight controller and motors. They provide a pulsating signal to the motors to drive a change in RPM and thus a resulting multicopter movement. A good ESC is paramount to stable flying. As brushless motors are multi-phased, normally 3 phases, you can't just apply DC power to turn them on. An ESC is basically a motor controller board that has a battery/signal input and a three phase output for the motor. Each ESC is controlled independently by a PPM signal that ranges from 1ms (min speed=turn off) to 2ms (max speed) in pulse width. The frequency of the signals varies between manufacturers, but for a multirotor it is recommended to use an ESC that supports a high refresh rate. A fast ESC will enable the motors to adjust quickly improving throttle response, drastically increasing stability and providing a more locked in feeling. Some ESC support programming, meaning you can reflash them with custom firmware. For instance, multirotor firmware such as SimonK is highly recommended by many for the best flight performance. However, caution should be applied as it is possible to ruin an ESC when attempting this process, therefore only a competent person with the correct equipment should attempt to reflesh an ESC. If you're after a good tutorial on how to flash your ESCs I recommend reading this.

When choosing an ESC you should match its ampere and voltage rating to your motors and LiPo. Current rating is usually given as 2 figures; a value which represents the maximum continuous current load and a higher burst figure which corresponds to a short term current (allowed normally for no more than 10-30 seconds) e.g. that produced at take off. It's recommend to select a speed controller allowing for a 20% safety margin. The other main ESC rating is the maximum voltage. This is usually expressed as the number of cells, e.g. a 6S LiPo (22.2v).

A lot of ESCs incorporate a BEC (Battery Elimination Circuit). This is a handy feature as it means that (within certain conditions) you do not need a separate receiver battery. They work by stepping down the main battery voltage to usually 5V. However, this process is inefficient and creates heat; the greater the differential between battery voltage and 5V the more heat generated. Consequently BECs (unless of the switching type) only work with a specified number of cells, often only up to a 3S LiPo and also within a specified current load. If not being used, the ESC’s BEC should be disabled by removing the middle (positive) wire to the receiver. For the reasons stated above, most large capacity ESCs do not have a BEC, but instead are almost always of the OPTO type (opto-coupled). OPTO ESCs differ from regular ESCs as the throttle signal between the motor and receiver circuits within the ESC are coupled via a light beam, not by a direct electrical connection. This is supposed to reduce radio interference between the motor and receiver. As a result, OPTO ESC require 5V to power the input side of the optocoupler, this is usually provided from the receiver, which in turn is powered by a separate battery or SBEC.

ESCs have three sets of wiring. On one side two wires, one black and one red that go to the battery or power distribution board. Also on the same side, you would normally have a 3 pin servo/receiver cable that usually plugs into a motor output on your flight controller. Finally the other side commonly has 3 outputs, which connect to the motor cables. If your motor is spinning in the wrong direction, simply swap the positions of two of these wires.

You should also give careful thought to the position of your ESCs within your craft. They are concentrated sources of magnetic interference, so locate them away from flight electronics such as the compass. Make sure they are ventilated, as they are likely to fail if they overheat. Some people recommend placing them out on the frame booms below the motors so that they are cooled by the prop wash; others caution against this approach as they are more vulnerable to damage and longer wires increase the risk of damaging voltage spikes.

Finally, some ESCs come pre-calibrated, however it's advisable to calibrate all ESCs before use by following the manufactures instructions.


By George (not verified) on

Hello, can these ESC brust more than 20A for 10 sec? Like 25 or 30A? I'm documenting a build and Ecalc says that i'll reach 20.08A for my 920kv motors and 1145 prop at maximum thrust (with a full battery). I'm bulding a filming platform so I will not do crazy flying but smooth and slow loiter. I know that most of the ESC's do offer a short burst value in their specs. Thank you.

By admin on

Hi, I can't find an official burst rating for them, however I've used them on 25A applications without issue. Most 20A ESCs have a burst value of 25-30A, so I think you will be fine to use them.

Add new comment

UK Express Shipping - Next Day Delivery on orders placed before 4pm

All information relating to shipping and delivery is stated here. Should you not find what you are looking for, please contact us.

UK Postage: Low value, small packages are sent using Royal Mail First Class. Larger and higher value orders are sent with Royal Mail First Class Recorded delivery. Consignments exceeding 2kg will be shipped using DHL or by a courier of our discretion. All high value orders are fully insured and will likely require a signature on delivery. Shipping cost are calculated once items have been been placed in your basket. We process orders Monday to Friday. Here at Flying Tech we pride ourselves on our quick turnaround of orders. If stocks levels allow, we aim to dispatch orders placed before 4pm the same day - please note that the DHL cut off for same day collection, next day delivery is 11AM. Otherwise orders will be dispatched within 48 hours of receipt of payment. A confirmation email will be sent when your items have been dispatched. If you wish to change your order, please contact us promptly, as we won't be able to make amendments once the order has been shipped.

FREE shipping in the UK on orders over £99 (this is a signed for service and insured to a maximum of £40). Please note that the offer only applies to orders with a total weight under 1Kg and that a few products are exempt from the offer.

We Ship Worldwide

International Postage: We are based in the UK, but ship to most worldwide destinations. Postage rates are calculated by the weight and shipment location, the price is quoted during the checkout. Low value order can be sent by Air Mail, but are not insured. Higher value, heavy goods will be sent with DHL or an alternative courier. Orders shipped outside the EU may be subject to customs charges. These charges are additional to any delivery costs and will need to be paid by the recipient.

Flying Tech International Shipping with DHL Express

For our international customers who require a rapid delivery we off a DHL Express service. DHL Express offers NEXT DAY delivery to most European destinations and a very fast delivery for countries further afield, generally 2-3 days. For country specific estimated transit times, please refer this download.

We reserve the right to modify, remove or add to any of these services at any time. We endeavour to ship all items as fast as possible. If you would like an alternative shipping arrangement to be made please contact us.