Since Arthur Arnot and William Brian created the first electric drill in 1889, technology has evolved dramatically. This includes the introduction of various drill types, such as brushed and brushless drills.
At a glance, there appears to be very little difference between a brushless drill and a brushed drill. They are designed to achieve the same thing but there are some important differences in how they function which means one type might be more suitable for a particular task.
In this article, we will explore brushless vs brushed drill options. This includes their effectiveness, required maintenance, and energy efficiency.
- Brushless drills use magnets and are more efficient, while brushed drills use carbon brushes and generate more heat.
- Brushless motors have longer lifespans and require minimal maintenance compared to brushed motors.
- Brushed drills are generally cheaper and easier to repair but may require regular brush replacement.
- Brushless drills are more responsive, adjusting their speed, torque, and power based on the task at hand.
Brushed vs Brushless Motor Comparison Chart
|Features||Brushed Motor||Brushless Motor|
|Performance||Reduction in torque as brushes wear out||Maintains high torque and power indefinitely|
|Operating Life||Brushes must be replaced after 50 to 60 hours of use||Can run for tens of thousands of hours|
|Efficiency||75% to 80% efficient||90% efficient|
|Size||Large and heavy||Small and lightweight|
|Maintenance||Regular brush replacement||Requires minimal maintenance|
|Structure||Brush friction-driven motor||Magnetic frictionless motor|
|Control||Manually adjustable torque and speed settings||Automatically adjusts its 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, a charge travels through the brushes and then into the commutator.
The charge is then transferred to the armature, which consists of copper wire. The charge magnetizes the copper wire, which presses against the ring of magnets. This causes the armature to spin, which drives the motor. When the power supply is cut off, the entire process stops quickly.
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. This typically 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 springs, connectors, or brush holders to keep them in permanent contact with the slip rings.
You can see evidence of this process when sparks are visible through the drill’s cooling vents.
Advantages of Brushed Motors
Although brushless motors have become an increasingly popular choice in recent years, there are still many advantages to a traditional brushed motor:
Easier to Maintain
Although brushed motors require more maintenance, it is also easier to keep them in perfect working order. Brushes have a limited lifespan, but they are easy to replace and this should be all it takes to keep your drill in ideal condition.
Plenty of Advice
Brushed motors have been widely used for decades, so it is easy to get advice regarding which models are the best and how to properly maintain them. This isn’t the case for brushless drills, which are still rarer.
Cheaper to Repair
As spare parts are readily available, they are cheaper. If you don’t feel confident about repairing the drill yourself, you should be able to take it to a local professional.
With a brushless drill, you would be better off replacing the entire drill instead of repairing it, given how complicated the process is.
Cheaper to Buy
There is a significant difference in costs when comparing the price of a brushed drill vs a brushless drill. Brushed drills might be an older technology, but they still have plenty of power for day-to-day use. As brushless drills become more popular, they should also become more affordable, but for now, brushed drills are the more economical option.
Disadvantages of Brushed Motors
Brushed drills are less energy-efficient than brushless drills. They usually have 75% to 80% efficiency, compared to the 85% to 90% efficiency of a brushless drill. This is because the motor spins at top speed all the time, so it will use energy that is not required.
Brushes Need Replacing
While it is helpful to be able to maintain your drill, the brushes wear out after 50 to 60 hours of use due to friction. This means there are added costs to owning a brushed drill. This is not the case with a brushless drill.
Brushed motors are susceptible to damage caused by debris and dust becoming trapped in the motor. When this happens, the brushes wear down more quickly than usual. If you intend to use your drill for masonry work, or other heavy-duty use, this is something to keep in mind.
As a brushed drill speeds up, it loses torque. This can become a problem if you intend to use your drill at full capacity to make holes in harder materials. If this is the case, try to buy the most powerful drill you can.
What is a Brushless Drill Motor?
As their name implies, brushless motors don’t contain brushes to transfer energy. They use far more modern technology to make your drill bit spin.
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.
Brushless 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 algorithms and is ideal for entry-level applications. It controls the power and speed of the motor but suffers from torque rippling. This is a fluctuation in the motor output as the rotor moves through the stator windings.
2. Sinusoidal Switching
Sinusoidal switching avoids torque rippling by providing each of the motors with currents that vary sinusoidally as the motor turns. This is a more complicated switching method but it simplifies the six-step process responsible for torque rippling.
3. Field-Orientated Control
Field-orientated control, or vector control, describes the control of torque and speed based directly 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% energy efficient. As there is no friction, unlike in brushed drills, far less energy is lost. If you have a cordless drill, this also means the battery’s charge should last as much as 50% longer.
Brushless drills are more responsive as the motor can automatically adjust the speed, torque, and power required for the job at hand. It can detect when you are drilling hard or soft materials and respond automatically. This will reduce the wear and tear on the drill motor and save you some money on maintenance and energy use.
Faster, Firmer, Longer
A brushless drill will provide greater speed, torque, and power than a brushed drill. As there are no brushes to cause friction, more of the energy will reach your drill bit. If you have never used a brushless drill before, you should expect a noticeable upgrade in performance.
A lack of brushes also means virtually no maintenance. There shouldn’t be a noticeable dip in performance with time, compared to the brushes on a brushed motor that typically need replacing after between 50 to 60 hours of use.
Brushless drills are smaller and lighter. Traditional brushed motors are larger and heavier, resulting in more substantial tools that require more strength to use for long periods.
Drill Lasts Longer
As brushless drills don’t endure the same friction and wear and tear as a brushed drill, they should last significantly longer. This also means the drill produces less heat, one of the biggest enemies of all drill motors and batteries. In some cases, a brushless drill can be as much as 50% cooler than a brushed one.
Disadvantages of a Brushless Motor
The main drawback of brushless drills is that they are more expensive and can cost as much as double their brushed counterparts. It is always tempting to buy the best power tool you can afford but you could be wasting money if you only need your drill for occasional jobs rather than a major project.
Replace, Not Repair
If your brushless drill suffers a malfunction, it might be best to simply buy a replacement rather than try to repair it. Brushless drills are complex machines and can be very expensive to fix.
If you don’t have the budget to do this, consider buying a brushed drill instead as they are much cheaper and easier to repair.
Brushed vs Brushless Motors: Why the Extra Cost?
As previously mentioned, brushless drills are more expensive than brushed drills. Let’s take a quick look at why that is the case.
Longer Run Time with Less Energy
Brushless drills have frictionless motors that use less energy, which makes them far more efficient. This means your drill will cost less to run, and cordless models have battery lives that are as much as 50% longer than cordless brushed drills. In practical terms, this means more time spent drilling and less spent charging.
Choosing a brushless motor means never having to replace brushes in your drill again. The brushes of a brushed drill will need replacing on average after 50 to 60 hours of use. This will vary depending on the type of materials you use your drill on.
Replacement brushes are very affordable, usually costing just a few dollars, but it is still an inconvenience to buy and replace them. A brushless model completely avoids that maintenance.
Much Longer Lifespans
Brushless motors should last for tens of thousands of hours, far longer than a brushed drill. A brushed drill will require a brush replacement after every 50 to 60 hours of use and the motor’s lifespan will usually be 1,000 to 3,000 hours.
In practical terms, a brushless drill will usually cost about twice as much as a brushed drill and should last four to six times longer. This makes a brushless model a better long-term investment.
Two drills made by Bosch highlight the difference in the prices of brushed drills and brushless models.
The Bosch PS32 Cordless Drill/Driver is a great example of a compact, brushless drill. When compared to a similar brushed model, the Bosch 18v Compact Drill/Driver, the brushless model is almost twice the price.
As brushless drills become more popular and widespread, their prices will likely fall, making them an easier option to buy. However, if you consider the longevity of brushless drills compared to brushed ones, they are a sound investment even at their current prices.
Brushless or Brushed: It’s the Torque of the Town
Ultimately, if you can afford the extra cost and anticipate using your drill frequently, you should choose a brushless model. They last longer, require less maintenance, and are more efficient.
However, this doesn’t mean you should disregard brushed drills. If you want a power drill for occasional jobs around your home such as putting up picture frames, a brushed drill will be an excellent purchase for far less money than a brushless model.
If you are a professional contractor and need a reliable drill for frequent work and heavy-duty drilling, you should buy a brushless drill. Its longer lifespan and reduced maintenance mean it will ultimately pay for itself, despite its higher initial cost.