A not too recent innovation in drone electronics, but something that is becoming more and more popular, is the use of 4 in 1 ESC s. They have been around for a little while, but used to be big and bulky, which made them difficult or even impossible to fit inside the typical FPV racing drone frame. Now that they are being made in much more compact form factors, their popularity is increasing. Today I’m looking at whether it’s worth making the move away from individual arm mounted ESCs for my next build.
4 in 1 ESC Benefits
A 4 in 1 brushless ESC allows you to move ESCs from the arms of your quadcopter into the centre stack with your flight controller. Compact builds can benefit, as they make wiring a lot simpler, removing the need for a power distribution board and separate BEC in some cases. By taking the ESCs off the quadcopter arms, they are protected in the main body and are less likely to be damaged in a crash or by a prop strike. It also means that arms can be made thinner, for less air resistance.
A 4 in 1 ESC typically weighs no more than four individual ESCs, but provides the benefit of less wiring and a more compact overall build. This is great for smaller frames, where the ESC wiring and power distribution board add to the clutter. Additionally the weight from the ESCs is now in the centre of your drone’s mass. Removing this weight from the arms will make it faster and easier for your drone to flip, roll and turn because there will be less weight away from the centre of mass and so less force is needed.
Bringing the ESCs into the centre of the drone does have its disadvantages though. There is much less cooling in the centre of the body than there would be out on the arms. The ESCs can therefore get hotter and are more likely to overheat. Components can easily overheat if they’re undersized for the application, so sizing is important. On top of this, a 4 in 1 ESC which has a single ESC failure, may need to be completely replaced, whereas individual ESCs could be swapped out a lot easier and at a lot less expense.
Most of these disadvantages can be overcome by properly sizing the ESCs for the application. Looking at the motor data and understanding the peak current that could be demanded based on your battery voltage and prop is important. When sizing individual ESCs you may for example select a 20 amp ESC because that is capable of providing a burst current of 25 or 30 Amps. When selecting a 4 in 1 ESC for the same application, I would recommend choosing an ESC with a high enough continuous rating to deal with the full current you expect. This will help to keep the temperature down and also makes it less likely that you will have a failure.
Different 4 in 1 ESCs available
There are a range of different amp ratings available as well as 4 in 1 ESC BLHeli_S and DShot. Various ESC sizes are now available for a range of different quadcopter sizes. Below are some options and details for 4 in 1 brushless ESC s available and where to get them.
4 in 1 ESC 30A / 35A
Popular for powerful racing drones, providing a consistently high current. Typically used with 5-6″ props and 2,300kV motors.
4 in 1 ESC 20A
Popular for powerful drones typically used for acrobatics, providing a reasonably high current. Typically used with 5-6″ props and 2,300kV or lower motors.
4 in 1 ESC 10A / 12A
Great for smaller mini-quads using 3-4″ props.
4 in 1 ESC 6A
For those really tiny micro builds using 2″ props.
If you’re creating a really compact build and could benefit from less wiring or you could benefit from having the centre of mass closer into the body, a 4 in 1 ESC could be great for you. By moving electronic components off the arms, they are protected and are not going to be damaged if you have a prop strike.
Some 4 in 1 ESC also include a BEC, which is great because for the majority of builds this will mean you no longer require a power distribution board. The ESC then sits where the power distribution board would have been and your overall build is a lot more compact.
As always, there is a trade off between price, size, weight, performance, durability and ease of use. In the case of 4 in 1 ESCs, there does not seem to be any difference in price, weight and performance, so for a compact solution, it’s a great option and one I will be using on my next build!
Prefer to buy ready built? Make sure you check out my Eachine Wizard X220 Review.