A wide range of power tools come in variants featuring both brushed and brushless motors. If, as a DIYer or a professional, you require a power drill, you must be wondering which variant of it suits your needs; the one with the brushed motor or the one with the brushless one.
Well, to come to a decision, you must consider several factors, such as the working principles of both, the cost of each, which one is more energy-efficient, the nature of the task at hand, and more.
Fret not, however, as below, we will get you up to speed with everything you need to know about the Brushed vs Brushless Motors debate so that the next time you need to bore a hole in your drywall, you know whether you need a brushed drill or a brushless one.
How Does a DC Motor Work?
Before diving straight into the brushed and brushless motors, let’s quickly inspect how a dc motor works, shall we?
The basic idea behind a dc motor revolves around magnets. There are two forms of magnets in the motor – mobile and immobile. The mobile magnets are called the rotor while the non-moving magnets are called the stator. The opposite charge between these two types of magnets allows a constant pull forward.
Now, for continuous rotation of the rotor, the non-moving magnets are actually permanent magnets whereas the moving magnets are actually electromagnets. As the rotation occurs, the electromagnets reverse their polarity such that the permanent magnets are attracted towards it.
On the other hand, when the electromagnets experience a similar charge as the permanent magnets, they push away the magnetic coil.
The way these electromagnets change their polarity is what differentiates a brushed motor from a brushless one.
What is a Brushed Drill?
A drill containing a brushed motor is called a brushed drill. Its motor consists of four essential parts:
- Permanent Magnets
- Commuter Rings
- Carbon brushes
The stator is composed of two oppositely charged permanent magnets. The coil or the rotor that acts as an electromagnet is what we call armature.
As for the commuter rings, they are fixed to the armature in a specific configuration and spin along with it. Finally, the stationary carbon brushes provide a pathway for the electric charge to flow from the power supply to each of the two commuter rings.
How Does a Brushed Drill Work?
When it comes to the working principle of a brushed drill, pretty much everything takes place in the armature.
So, when the charge flows to the armature, it powers up and the charged coil is pulled towards the oppositely charged permanent magnet. Meanwhile, the commuter ring above the coil also changes connection from one carbon brush to the other.
As soon as it comes into contact with the other carbon brush, the coil’s polarity reverses and it gets pulled towards the other permanent magnet.
In other words, when the commuter ring reaches the negative carbon brush, the coil is attracted to the positive permanent magnet and when it reaches the positive carbon brush, the coil is attracted to the negative permanent magnet.
Due to the carbon brushes being in pair, both the positive and negative sides of the coil are pulled towards negative and positive permanent magnets respectively, at the same time.
What is a Brushless Drill?
In a Brushless drill, there are no commuter rings and carbon brushes. Instead, there is an electric controller and a sensor. Also, this time around, the permanent magnets act as the rotor and are located inside whereas the stator, consisting of an immobile electromagnetic coil, is located outside.
How Does a Brushless Drill Work?
When the sensor tracks the position of the rotor, it sends out signals to the electric controller which in turn, powers up the coil according to the charge it needs to either attract or repel the permanent magnet.
Like charges result in a push while unlike charges result in a pull; this push and pull motion keeps the permanent magnets (the rotor) moving.
Advantages of Drills with Brushed and Brushless Motors
Now that you have familiarized yourself with the definitions and mechanisms of both brushed and brushless drills, to pick the right one for your use, you must be aware of the advantages that each one of the brushed and brushless motors has over the other.
A brushed motor has a relatively simple design and the required parts to make it are much cheaper than the ones required to make a brushless motor. On the contrary, the electronic communicator in brushless motors is a newer technology and hence, it is more expensive.
To give you an idea, a brushless drill costs twice as much as a brushed one.
With no carbon brushes rubbing against anything, no energy is dissipated due to friction, making brushless motors more energy-efficient than brushed motors.
On average, a drill with brushless motors can run at least half as long as the ones with brushed motors.
Due to the sensory ability of the electric controller in a brushless motor, it is able to adjust its power supply, torque, and speed according to the task you need it for.
For instance, if you are driving screws into your drywall, it will lower down its power to accomplish the required results. The power that is conserved in the process, in turn, adds to the efficiency of the motor.
On the other hand, a brushed motor always has the same power and speed, regardless of the task at hand.
While brushes limit the power of the brushed motors by causing friction, with no brushes to slow things down in brushless motors, they are able to attain much higher power, torque, and speed.
A drill composed of brushed motors needs to have its brushes replaced after around every 50 hours of use.
With no brushes present in a brushless motor, you can avoid any such maintenance cost altogether.
Drills with brushless motors are nearly 25 percent more compact than ones with a brushed motor. The small size coupled with the lightweight means that the drills with brushless motors are not only easy to carry but can also be used in tight corners.
The no-brushes design of brushless motors corresponds to no friction which in turn means less wearing down and less heat loss.
Furthermore, any heat that develops inside a brushless motor is located on the exterior, which causes it to dissipate faster.
Consequently, a brushless motor lasts way longer than a brushed motor.
Lower Torque Ripple & Acoustic Noise
Acoustic Noise is basically the mechanical pulsation of energy onto the rotor. It results in vibration and noise, particularly at low speeds, and hence, it is directly linked with acoustic noise.
Due to the electrical communication system in brushless motors, current transfers gradually from one coil winding to the other, resulting in lower torque ripple and hence, lower acoustic noise.
Frequently Asked Questions
Are Brushless Motors Louder?
No, brushless motors require less power to function. Hence, they are quieter as compared to their brushed counterpart.
By now, you might have figured out whether you need a brushed drill or a brushless one. If not, we have got you covered.
As is apparent from the guide above, whether it’s energy efficiency, maintenance, noise, or anything else, brushless drills seem to have a clear edge on their brushed counterparts. The only advantage that a brushed drill carries is its lower initial cost.
As a professional who has plenty of heavy-duty tasks on his to-do list, a brushless drill is probably your most sensible bet. On the contrary, if you are DIYer who infrequently needs to handle lighter projects, you can go with either of the two, although remember that a brushless drill comes with added benefits.