Brushless goes best
Remember when LPs lost favour to CDs? Or when even the inner workings of car engines became more computer technology than old-school mechanics? That same analogue to digital revolution is now underway with power tools and some manufacturers are investing heavily in the hope of making it a permanent change.
Brushless technology is now at the heart of product strategies from leading manufacturers, and it is taking pride of place on retail shelves throughout Australia. This switches power tools from using carbon brush-based engines that have changed very little over the past fifty years or more, to smaller micro-processor-based power generators. With no moving parts and both smaller and lighter to boot, these engines are more efficient, easier to maintain, and longer-lasting than traditional power tool systems.
“Customers want the machine to run for as long as possible and be as light as possible,” Richard Steele, product manager from Hitachi Power Tools told Australian Hardware Journal. “Brushless tech products achieve just that.”
Brushless products are not brand new. Rather, the idea has been in research and development circles since the 1960s. The digital systems that are at the heart of most power tools have, however, only been in development since around the start of this century.
Panasonic brought out the first brushless models, starting with an impact driver, to the US and European markets in around 2006. Since then, take up has been relatively slow, though increasing more rapidly in recent years. Panasonic still maintains a regular range of power tools, while Milwaukee, DeWalt, and others have also introduced brushless tools as alternatives to regularly-powered equipment, without any moves to replace them.
Steel says the process of convincing customers is always slow when it comes to new concepts and technology. “It can be difficult to introduce new concepts that look the same from the outside.”
There are also other links in the supply chain that need to be brought on board. Steel recalls holding several long and complicated meetings with marketing teams and retailers when first bringing Hitachi’s brushless tools into Australia. “We had to take them through step by step how it all worked,” he said.
Now, retailers are offered free or subsidised workshops with the product management team to really convince them of the advantages of brushless technology.
The team at Makita is also embracing brushless technology in its product range, albeit with the same tentativeness. Damien Taylor, product coordinator, says the brand’s latest offering is the mobile brushless impact driver BTD147RFE/Z, released on to the Australian market in late January this year. This claims to be the world’s smallest such tool, measuring just 129mm across and weighing just 1.5kg. Makita has also packaged the brushless engine technology with dust and drip resistant coating to ensure the tool lasts as long as its new engine, Taylor noted.
How it works
A typical brushless motor has permanent magnets which rotate and a fixed armature, eliminating problems associated with connecting current to a moving magnetic field creator, typically a powerful magnet in brushed engines.
An electronic controller replaces the traditional brush-and-commutator assembly of the brushed DC motor, which continually switches the phase to the windings to keep the motor turning. The controller performs similar timed power distribution by using a solid-state circuit rather than the magnetic power of the brushed setup. Commutation then comes via software using a microcontroller or computer.
The maximum power that can be applied to a brushless motor is limited almost exclusively by heat; too much of which weakens the magnets, and may damage the winding’s insulation. Brushless motors avoid this problem as, without contact, there is less energy not transferred directly to where the tool is directing it. In brushless tools, this excess energy would typically be converted into heat.
Big advantages, small price rise
But most importantly, these motors contain no moving internal parts, and no energy-sapping friction. That’s the reason behind the more efficient energy use, which also translates to easier maintenance for the end user.
With traditional power tools, owners need to continually check and sometimes replace the carbon brushes involved with the motors. The nature of that traditional technology involves the carbon brush – shaped like small coil – conducting current between stationary wires in a rotating shaft. This naturally involves some friction, and over time the brush will wear down, reducing performance until eventually connectivity is lost forever – or at least until the brush is replaced (in higher-quality tools where self maintenance is an option).
The new micro-processor-based brushless motors do away with this maintenance issue, saving users time, money, hassle and worry.
The motors are also durable against the kind of long, continuous operation that would quickly drain other machines dry. With lower heat production from the brushless motor, the typical temperature rise from hard industrial application and/or continuous use is significantly reduced to manageable levels.
Brushless motors are also safer in hazardous environments where sparking could be a risk factor.
The potential savings are high, far higher than the typical additional outlay required for brushless tools. Buyers can expect to pay around $50 more for a tool with this technology, all other brands, factors and specifications being equal.
With most tools currently on the market targeting trade professionals, the higher price represents only a small investment in something that will naturally last users a lot longer, and will be cheaper, lighter, and easier to use on the job.
Now on the market
While brushless technology has been relatively slow to take off, it is now a feature of products from a range of manufacturers distributing to the Australian market. The following descriptions are not an exhaustive list of what is currently available – but do give an indication of how the technology is being adopted and taken up locally.
Hitachi claims to have the strongest presence in the brushless technology space in Australia, with a nine-piece offering of cordless options, all aimed at the professional tradesperson. The range includes an impact (hammer) driver drill, driver drill, impact driver, impact wrench and electronic pulse driver, all with 18V batteries. 14.4V versions of the driver drill, impact (hammer) driver drill, impact driver and impact wrench are also part of the lineup. Steel says each one also boasts a multiple protection circuit, which will shut down a tool at risk of power overload, overcharging, or the battery becoming completely drained. “Each of the tools has a sensor to stop that,” he said.
As well as the just-launched mobile brushless impact driver, which hit Australian shelves in January (see: above), Makita has five other offerings in the brushless space. These include an impact wrench and high-torque drill. Each is connected with a Lithium-Ion battery for enhanced power efficiency and faster recharging.
Panasonic, which was first to introduce brushless technology to the Australian market, now has five tools featuring brushless engines – each targeting professional tradies – available locally. They include three different models of cordless impact drivers and two different models of cordless impact wrench.