Since its creation in 1889 by Arthur Arnot and William Brian, the electric drill has improved dramatically with design and technology advancements.
To the untrained eye, there is little difference between a brushless drill and brushed drills. They do the same thing, so why would you need to worry about the way the drill motor works?
You should care because there are real differences that have an impact on efficiency, maintenance, and power usage.
So, brushless vs. brushed drill? Let’s find out.
The Truth About Brushless Vs. Brushed Drills
The difference between brushless and brushed drills comes down to the motor. Brushless drills use magnets to generate power. Brushed drills use carbon brushes to create movement. Brushed drills use friction which creates heat, but brushless drills are frictionless, so they generate less heat. This makes them more efficient and reliable.
Brushed vs. Brushless Motor Comparison Chart
|Features||Brushed Motor||Brushless Motor|
|Performance||Loses torque as brushes wear out||Maintains high torque and power endlessly|
|Operating Life||Brushes need replacing every 50 to 60 hours of use||Runs for tens of thousands of hours|
|Efficiency||75 to 80 percent efficient||90 percent efficient|
|Size||Large and heavy||Small and lightweight|
|Maintenance||Frequent (to change the brushes)||Requires minimal maintenance|
|Structure||Brush friction-driven motor||Magnetic frictionless motor|
|Control||Manually adjustable torque and speed settings||Thinks for itself and adjusts the power and torque depending on the job|
How Does a Drill Motor Work?
A traditional motor in a power drill consists of four main parts:
- Carbon brushes.
- A ring of magnets.
- A commutator.
- An armature.
When power is applied, the charge travels through the brushes and then into the commutator.
The charge gets transferred to the armature, which consists of copper wire. The charge magnetizes the copper wire, and presses against the ring of magnets. This causes the armature to spin, which then drives the motor.
The whole thing stops when the power cuts out.
What are Brushes?
A carbon brush is an electrical contact that conducts a charge or current between stationary wires and the moving parts of the motor. Typically, this includes the rotating shaft. It is part of the stator of an electrical motor, sending a charge to the rotor, in this case, the shaft.
Brushes come in different shapes and sizes, with the most common being square or rectangular. They are typically made of graphite and have either springs, connectors, or brush holders to keep them in permanent contact with the slip rings.
The best evidence of your brushes at work is when you see sparks through the drill cooling vents.
Advantages of Brushed Motors
While the latest trend is to buy brushless motors, there are still many advantages to a traditional brushed motor.
Easier to Maintain
Although brushed motors require more maintenance, it is easier to keep them in perfect working order. Brushes have a limited lifespan, so most of the time, nursing your drill to good health involves swapping the brushes.
Plenty of Advice
Brushed motors have been around for decades, so getting the right advice on how to perform maintenance is easy. There is a lot of information out there.
Cheaper to Repair
Because the spare parts are readily available, they are cheaper. And if you don’t feel confident about undertaking a repair, there is always the option of taking it to a professional.
With a brushless drill, you would be better replacing the entire drill instead of repairing it.
Cheaper to Buy
There is a significant uplift in costs when comparing the price of a brushed vs. brushless drill. Brushed drills are older technology, but for day-to-day use, they still give you all the power you’ll need.
Over time, this difference will level out, but until then, brushed drills are still a smart buy.
Disadvantages of Brushed Motors
Brushed drills are inefficient. When you compare the efficiency of a brushless motor, at 85 to 90 percent, a brushed motor manages 75 to 80 percent. The reason for this?
The motor spins at top speed all the time, so it uses energy you don’t need.
Brushes Need Replacing
While it’s a good thing to be able to maintain your drill, the brushes wear out every 50 to 60 hours of usage. That means there is an added cost to owning a brushed drill. This is not the case with a brushless drill.
All that friction creates heat, and this is what wears down the brushes.
Brushed motors are susceptible to damage from debris and dust getting trapped in the motor. When this happens, the brushes wear down faster than usual. If you plan on using your drill for masonry, or heavy usage, this could be a problem.
As your brushed drill speeds up, it loses torque. This only becomes a problem if you intend to use your drill at full capacity and need to drill through harder materials. If so, get the most powerful drill you can.
What is a Brushless Drill Motor?
It’s time to state the obvious, but brushless motors have no brushes. The whole concept of how a motor works is flipped on its head.
A brushless motor uses magnets instead of carbon brushes to generate power. Brushed motors have permanent magnets on the stator and electromagnets on the armature.
These motors have permanent magnets situated on the rotor, and electromagnets on the stator to spin the rotor.
There are three main types of algorithms used on brushless motors:
1. Trapezoidal Commutation
Trapezoidal switching is the simplest of the three and is ideal for entry-level applications. Trapezoidal switching controls the power and speed of the motor but does suffer from torque rippling. That is a fluctuation in the motor output as the rotor moves through the stator windings.
2. Sinusoidal Switching
The idea is that sinusoidal switching removes the torque rippling by providing each of the motors with currents that vary sinusoidally as the motor turns. It is a more complicated switching method, but it removes the six-step process responsible for torque rippling.
3. Field-Orientated Control
FOC, or vector control, describes the way control of torque and speed are directly based on the electromagnetic state of the motor. It controls the motor’s variables of torque and flux (the electrostatic field).
Advantages of Brushless Motors
Brushless motors are 90 percent efficient. No friction through the brushes means that no energy gets lost as a result. If you have a cordless drill, it also means the battery charge lasts up to 50 percent longer.
Brushless drills are more responsive because the motor can adjust the speed, torque, and power needed to cater to the job at hand. It knows when you are drilling hard or soft materials and responds automatically. This saves you wear and tear on the drill motor and energy costs.
It also prolongs the life of your motor, which means less expense in the long run.
Faster, Firmer, Longer
You get more speed, torque, and power with a brushless drill. Without brushes to create friction, more of the energy gets translated into performance. Expect a significant uplift.
No brushes mean virtually no maintenance. You won’t experience a drop in performance either as the brushes on a brushed motor typically need replacing every 50 to 60 hours of continuous use.
Brushless drills are smaller and lighter. Traditional brushed motors are heavier and larger, making for more substantial tools.
Drill Lasts Longer
Without the friction and the wear and tear a brushed drill motor gets, a brushless drill will last longer. It also means the drill produces less heat, which is the biggest enemy of drill motors and batteries. In some cases, a brushless drill could be 50 percent cooler.
Disadvantages of a Brushless Motor
The distinct disadvantage is that brushless drills are more expensive. They can cost as much as double their brushed motor counterparts. We get that you want the best power tool for your dollars, but unless you are embarking on a significant project that requires the best drill, is the added expense worth it?
Replace, Not Repair
Should you suffer a malfunction, the chances are you would be better off buying a new drill. Brushless designs are complicated and often expensive to fix.
If you don’t have the budget to do this, consider your drill choice carefully. Brushed drills are easy to repair.
Brushed vs. Brushless Motors: Why the Extra Cost?
As we’ve said, brushless drills are more expensive, and we need to look at the reasons why.
Longer Run Time with Less Energy
Brushless drills are more efficient because they have a frictionless motor that uses less energy. It means your drill will cost you less to run, and if you have a cordless variety, it will boost the battery longevity by up to 50 percent. That means you get more use out of it between charges.
Imagine never having to replace the brushes on your drill. Brushless motors offer that.
The brushes on a brushed drill will need replacing every 50 to 60 hours, on average. This does depend on the amount of use the drill gets.
Replacement brushes are relatively inexpensive, costing just a few dollars, but it is still an inconvenience having to do it. With a brushless model, none of that is necessary.
They Last Forever
Brushless motors last for tens of thousands of hours. That’s much longer than the useful working life of a brushed drill. The lifespan of a brushed drill is just 50 to 60 hours between brush changes and 1,000 to 3,000 working hours for the motor.
Let’s equate this into cost. If a brushless drill costs you around twice the price of a brushed drill but lasts on average four to six times longer, it makes financial sense to buy a brushless.
Here are two drills made by Bosch that highlight the difference in the price of brushed drills and brushless models.
This Bosch PS32 Cordless Drill/Driver is a great example of a compact, brushless drill. When we compare it to a similar model, the Bosch 18v Compact Drill/Driver, we see the stark price difference between the two. The brushless model is almost double the price.
Over time, the price of brushless drills will fall, giving parity between the two. But even when you factor in the longevity of brushless drill compared to their inflated price-tag, you are still making a sound financial choice if you buy one.
Frequently Asked Questions
How long do brushless motors last?
Brushless motors last for tens of thousands of hours. They are the most efficient drill motors because they operate with a frictionless drive. Unlike brushed motors, there is no need to replace brushes, which means they require less maintenance.
The principle advantage of a brushless motor is that they don’t heat as much, which is the biggest killer of drill motors. Also, because they are more efficient, there is less strain on the motor, which increases the lifespan.
Are brushless motors waterproof?
Brushless motors are not waterproof, but they will take a splash of water. Working in the rain or snow is fine, as long as you dry the motor completely.
Be warned, while some brushless motors are branded as waterproof, we would recommend you do not submerge your drill under the water.
Are brushless drills intrinsically safe?
In general day-to-day use, brushless drills are safe. However, brushless drills are not intrinsically safe as they have the potential to throw off sparks. If you are working in a flammable atmosphere, then hot working protocols should be adopted.
How do you tell if a motor is brushed or brushless?
The easiest way to tell the difference is to look into the air vents of your drill with the motor engaged. If you see sparks, then the likelihood is you have a brushed variety.
The other way to tell is to get a feel for the drill when you use it. It will adjust the torque automatically depending on the task it is used for. Also, brushless motors make less noise, so if you think your drill is quieter, you probably have a brushless motor.
The third way to tell is to look at the size and weight of the drill. Brushless motors are smaller and more compact, making them lighter and more nimble to use.
Brushless or Brushed: It’s the Torque of the Town
So, the message is if you can afford the extra cost, go brushless. They last longer, need less maintenance, and are more efficient.
However, don’t write off brushed drills completely. If you want a power drill for those occasional jobs around the home, then a brushed drill will suffice.
Also, if you are a professional and need a reliable drill that lasts forever, then you are probably going to need a brushless drill.