The Benefits of Brushless Motors in Power Tools
Here at SGS, we’ve had our eyes on some brushless motor power tools for quite a while. Brushless power tools aren’t exactly a new technology; we’ve seen them in high end drills and drivers for years - but when it came down to it - even the most serious of DIY users struggle to afford one. The technology always seemed a little out of reach for the average toolbox. Now with a new generation of affordable brushless power tools coming through the ranks, we thought it was worth showcasing some of the high end features of these clever tools.
Whether you’re in the market for a new drill/driver, you want to upgrade your old impact wrench, or you just want to learn a bit more about how these innovative power tools work - this guide is for you! We’ll showcase some of the benefits of a brushless motor, and help you decide whether it’s worth making the switch.
What is a brushless motor?
Let’s begin at the beginning. The power tools in your toolbox almost certainly contain motors with carbon brushes. Let’s have a quick look at a traditional electric motor. It’ll contain five basic components: a rotor (or armature), commutator, brushes, a shaft and a stator (field magnet).
An electrical current is fed from the battery to the brushes - the brushes physically touch the commutator. The current can then pass through to the coiled armature, making a magnetic field, and allowing the armature to rotate around the shaft. The basic principle is that the more current you send through the brushes to the armature, the stronger the magnetic field you’ll make, thus giving you a faster rotation. Drills and drivers utilise this rotational force to make the accessory bit spin, boring a hole or driving a fastener.
Because the brushes are physically touching a moving element, friction causes energy loss, an increase in heat and wearing of the component parts.
Milwaukee Brushless Circular Saw
The Milwaukee Circular Saw has a 50° bevel capacity with magnesium upper and lower guards which provide durability for impact resistance. Maximum durability is achieved with the circular saw with the magnesium shoe which also helps to reduce the weight of the saw. Safety is integrated into the machine with an integrated dust blower which keeps the cut line clear and hang hooks for safe storage of the tool.
Milwaukee Brushless Reciprocating Saw
The Milwaukee reciprocating saws motor gives around x5 longer motor life and up to 30% faster cutting. The saw is equipped with a gear protecting clutch that extends the motors life a due to it absorbing high impact forces that can be caused when the blade suddenly locks-up. An adjustable shoe can also be used for optimal use of the blades and a bright LED light is also on the machine for maximum usage of the saw.
How’s a brushless tool different?
Well first off - there's no carbon brushes, and the commutator is gone too, but those aren't the only differences. The locations of the magnets and windings are reversed in this set up. The magnets sit on the actual shaft of the power tool and the cooper windings spin with the armature. Instead of brushes moving a variable current through to a commutator, now we have a small circuit board coordinating the energy delivered to the windings. Now you’ve got a smart tool that can adjust itself to the task at hand.
Instead of constantly trying to draw the highest possible current - your tool is pulling only the current it needs. Just think what that’ll do for your battery life.
So, why choose a brushless power tool?
Now you’re thinking - is a brushless power tool right for me? Innovation aside, what are the practical benefits of choosing a brushless power tool, over say, a more traditional brushed motor? When you purchase a brushless power tool expect a longer-lasting, lightweight, incredibly efficient, smarter tool.
Brushless Power Tools are Longer-Lasting
No brushes means your motor is virtually friction-less. The Milwaukee generation 3 fuel impact driver boasts lower running temperatures, less energy loss and a far slower rate of wear-and-tear on the power tool. In short, you’re going to get a much longer product life from a brushless tool, compared to a conventional alternative. There’s a reason why all Milwaukee brushless tools come with a 3-year warranty.
The Milwaukee M18FID2-0 M18 FUEL ¼” Hex Impact Driver is the fastest, most compact, and most powerful tool in its class. The powerstate™ brushless motor delivers up to 226Nm of torque increasing your productivity for the most demanding fasteners on the job. Whilst redlink plus™ intelligence ensures maximum performance and protects from overloads, heating and or over-discharge.
Brushless Power Tools are Smaller
Due to the design of a brushless motor, overall the component parts are smaller and more lightweight when compared to your standard tools. This is always a huge benefit when purchasing any battery powered tool, where it’s all about optimum manoeuvrability and versatility. The smaller the tool, the tighter spaces you can get to.
Powered by a smooth digital brushless motor and fuelled by a high-tech Samsung Li-Ion battery, the Kielder KWT-002 1/2” Impact Wrench delivers high torque performance (430Nm) in a compact size (152mm length). Weighing only 1.7kg (including the battery) it is well balanced and comfortable to operate, even in those tight / awkward areas. Makes easy work of assembly or disassembly tasks around the garage and workshop.
Brushless power tools are more efficient
Because brushless tools have the current regulated by a circuit board rather than a direct connection, a brushless tool will only ever draw the power it needs for the application at hand. A good example is drilling in plaster board. For brushed drills, the motor works at full power for each bore hole, wasting valuable battery time. This generation of Milwaukee smart tools will “sense” the very limited resistance of the plaster board, and draw only the current it needs to do the work.
Now switch over to drilling a hard wood and the drill knows the resistance has increased and can intuitively match the draw as required. Milwaukee boasts up to a 52% reduction in battery draw when comparing brushless and convention motors - that’s a lot of extra drill holes!
Compare and Contrast : The Ryobi ONE+ 18V Cordless Brushless Percussion Drill
Sometimes it’s hard to express exactly how big a jump in innovation a new feature is. This comparison between two 18V Ryobi drills. One has a conventional brushed motor and the other a new brushless motor.
If you were ever going to upgrade your sage old drill/driver - there’s never been a better time to do so.
Hopefully, this guide has given you a good idea about what the benefits of brushless motors are, and how they can improve the quality of your projects. Overall, it’s worth remembering that even though a brushless tool will cost a little more than it’s conventional counterpart, you’ll more than save that extra initial expenditure over the tools life - and the extra power and battery efficiency is a great bonus too!
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