Cordless impact drivers have been gaining popularity for some time now. Today, it would be hard to find a professional shop that didn’t have at least one. If you’ve priced them, however, you may have noticed that they fetch a different price than a typical cordless drill. There’s a reason for that: Despite the similarity in appearance, they’re completely different tools. An impact driver, like Makita’s BTD130FW 14.4 Volt Cordless Impact Driver, may look like a sort of wimpy drill/driver, but in reality, it’s a much more sophisticated mechanism, and provides an entirely different fastener driving experience.
How does an impact driver work? There are several variations in mechanical design, but in essence all impact tools all work like this: A rotating mass in the tool called a “hammer” is accelerated independently of the “anvil” – the output shaft that engages with the head of the fastener. When the hammer has built up a certain amount of energy, it is brought into contact with the anvil, creating an impact which instantaneously applies torque to the fastener. The cycle repeats and repeats, on the order of thousands of impacts per minute. The result is a high level of torque delivered to the fastener with very little effort on the part of the user.
There’s really no comparison between an impact driver conventional drill/driver when it comes to fastener driving force. The Makita BTD130FW impact driver, for example, delivers a maximum torque of 1240 in. lbs., compared to less than 400 for a typical cordless drill of the same voltage. But the more important difference between a drill/driver and an impact driver is in the delivery. Unlike a drill, an impact driver transfers high peak levels of torque directly to the fastener, and very little to the handle of the tool. Mechanically, the comparison is roughly the same as driving a nail with a hammer versus pushing one in with a rock.
In terms of fastener driving speed and comfort, most impact drivers will run circles around a cordless drill. But when you’re in the market for one, the unique qualities of individual models are worth careful consideration. In actual practice, the performance of the tool will depend on a number of factors: motor efficiency, quality and design of the impact mechanism, and the power and reliability of the battery. Here, the Makita brings a lot to the table, including a four pole motor that generates energy every 90 degrees (instead of every 180), steel ball bearings for durable support, and proprietary, heat-hardened hammer and anvil designed for longevity. There’s also a built-in work area illuminating LED light that – a small amenity that you’ll gain a big appreciation for the first time you operate the compact BTD130FW inside the a dark cabinet.
But what really sets the Makita apart from a great many other contenders is the battery system. The BTD130FW is powered by Makita’s state of the art XLT Lithium-Ion series 14.4 volt battery. As may be common knowledge by now, lithium-ion batteries offer several advantages over Ni-Cad or Ni-MH batteries (the other two types available for cordless tools) including twice the number of battery life cycles, greatly decreased self-discharge when stored, less power drop-off toward the end of the cycle, and best of all, no discharge “memory”, meaning that the batteries don’t have to be run down to nothing periodically for conditioning. Along with that, they’re much lighter than their nickel-based counterparts and don’t pose the environmental problems on disposal.
The technically sophisticated XLT charging system makes sure you get the most out of your batteries – on an individual basis. A CPU chip in the charger communicates with a memory chip in each battery and custom tailors the charging cycle to the battery’s usage history. The system’s “Active 3 Control” regulates voltage, current and heat, while a built in fan in the charger cools the battery to promote maximum battery lifetime work. It’s truly the best you can do in cordless tool power supply, and is likely to be a deciding factor for many.
If you are using a cordless drill to drive screws, switching to an impact driver will have an immediate and marked effect on your attitude toward fastening in general. That’s no exaggeration. In fact, using an impact driver for the first time can be an almost eerie experience – screws slide in so effortlessly; there’s very little pressure required to keep the tip of the driver engaged in a screw, and because torque is transferred more directly to the fastener, very little sensation of the handle of the tool wanting to twist out of your grip. If you spend a fair amount of your time driving screws and other fasteners, the payback in speed, convenience, comfort and reduced fatigue you’ll get from the Makita BTD130FW Cordless Impact Driver will make the investment feel like a bargain.