Brush vs Brushless Drill

Are Brushless Drills Better?

brushed vs brushless Drill comparison

Whether you like to stay informed with developments in the power tool industry or are in the market for a new drill, there’s one thing you may have come across that you might not understand. That is, what is the difference between brushed and brushless drills? You’re in luck, as that’s exactly what we are going to look at in the following post.

As well as explaining the difference between the two, we will look at the pros and cons of each, to give you a better idea as to which you should invest in.

 

Abnormaal [CC BY-SA 3.0 (http://creativecommons.org/licenses/by-sa/3.0/)]

Understanding the Differences

To understand the differences between brushless and brush motor drills, it is helpful to understand what actually drives electric motors. Regardless of whether it’s a brushed or brushless model, magnets are what powers the rotary or spinning action in the shaft of the motor. The same principle is at work that you probably experienced when you used to play with magnets and try to push the S of a magnet against the N magnet.

 

How Brush Motors Work

For brush motors, the power supply is run through two little carbon filament blocks (known as brushes) at either end of the shaft. Then these brushes make contact with a part of the motor shaft known as the commutator, which takes the electric current generated by the brushes and transfers it into the armature, another part of the motor connected to the shaft.

What is the armature? This is basically a collection of copper wires wrapped up tightly into compacted coils and when the current of electricity is passed into it, it creates an electromagnetic field. Outside of the motor, there are S and N magnets that are fixed in place. Once the electromagnetic field and the armature is charged, the magnets create opposing forces and that cause the motor to start spinning.

 

How Brushless Motors Work

It’s a little bit more complicated in brushless motor setups, even if they do rely on the same process involving opposing magnetic forces. As noted above, in a motor with brushes, the armature is connected to the shaft of the motor and on the outside at opposite ends there are the two magnets. In a brushless motor this is reversed with the armature placed outside the motor and fixed and the opposing magnets on the actual spinning part or rotor of the motor.

How is the power is transferred in the motor if it doesn’t have brushes? Another bit of ingenious electrical circuitry is required. This is normally a very small and expensive board that provides the motor windings with power and houses a sensor that detects whether the rotor is moving or not, and the exact location of the motor at all times. The tool’s electronics coordinate when to fire the different coils and when to reverse the polarity if we want the motor to run backwards.

 

Pros and Cons of Brushed and Brushless Motors

Now that you understand how each type of motor works a bit better, before deciding whether you want to buy one or the other, it’s worth highlighting the pros and cons of each type.

 

Brushed Motor Pros

Brush motors are the more common and popular, and that is due to many of the distinct advantages that come from using them, such as:

  • The wiring is a lot simpler in a brush motor than a brushless, as noted earlier. Brush motors can be connected to a DC power source and controlled with the touch of a button or flick of switch.
  • A simpler design means they cost less to manufacture.

 

Brushed Motor Cons

The above advantages are why many people prefer brush motor drills, however, it’s worth also keeping in mind the following downsides:

  • They have a shorter lifespan, because the commutators and brushes are always in contact with the shaft and they will wear out.
  • They are very noisy. This is because of the commutators and their switching action of creating and breaking circuits produces a lot of both electromagnetic and electrical noise.
  • They are a lot less efficient.

 

Brushless Motor Pros

Now, it may have taken some time, but steadily brushless motors have become incredibly popular in the last few years, and a lot of that is probably due to the extensive and distinctive advantages that come from using them, such as:

  • They tend to have a much longer lifespan and don’t have any brushes that wear out and need to be replaced.
  • They are very low maintenance, again, because there are no brushes that need to be replaced.
  • They are highly efficient. No components touching and creating friction translates into increased performance and longer run times.

 

Brushless Motor Cons

While many of the advantages listed above definitely make them stand out, there is only really one notable downside that is worth considering when you are buying a new drill. They cost a lot more money, initially at least, due to the more complicated setup and additional componentry involved.

 

Which Should You Choose? Brush or Brushless Drill

Obviously, with anything like this, it is down to personal taste and preference. You need to weigh up the pros and cons of each. Although people are more familiar with brush motor drills, there is a lot of definite downsides to using them. Whereas brushless motors are efficient, quieter and last longer.

As well as considering the above, you need to also think about the cost and how often you are going to use the drill. If it’s just going to be used for the occasional odd job, for instance, it may not be worth investing in an expensive brushless model. However, if you are going to be using a drill a lot, whether it’s as part of your profession or you’re carrying out extensive work, day in day out around the home, the initial cost may be worth it in the long run.

For more info on choosing the right drill, check out my review of cordless drills here.

 

Steve Wright

Steve Wright is a general contractor who over the last 30 plus years has built hundreds of new homes, ranging from first time affordable homes to multi-million dollar custom homes and everything in between.

This Post Has One Comment

  1. This reminds me of my days at the University when I did an Electrical Engineering course on Types of motors i.e. brushed and brushless motors. You have explained it so well with regard to how these motor types are applied in making of these 2 drill types, that even a person without a background in Electrical Engineering training can understand this. Thanks for sharing this informative article.

Leave a Reply

Close Menu