MRO Today - Cordless impacts come of age

Cordless impacts come of age

Cordless impact drivers and wrenches have finally equaled their pneumatic cousins in power. What can they do for you?

by Tom Hammel

Ain’t technology great? The power-to-weight, durability and run time delivered by the current best-of-breed cordless impact drivers and wrenches just keeps getting better with each generation, with no end in sight. At this rate, it won’t be long before these tools can do jobs their human users can’t. They probably can already.

Fortunately, finesse is the flip side of power, and while the “juice” continues to rise, so does the range of jobs these tools can do and the quality of finished work they can deliver. One case in point is this issue’s cover story on Beta LED, which is now shifting some formerly pneumatic-only applications to cordless impact drivers.

All juiced up
By now, you might expect every best-in-class cordless impact driver to be powered by lithium-ion batteries. But the industry is still in transition, and just because lithium-ion has “arrived,” that doesn’t mean other power sources are all dried up. Not yet.

Bosch for example uses NiCd (nickel-cadmium) to power its current heavyweight champ, the 18-volt model 21618 HTIW 1/2-inch High-Torque Impact Wrench. This tool delivers 350 foot-pounds of torque and weighs in at 7.5 pounds.

Nothing, however, beats lithium-ion for sheer power-to-weight. Makita’s LXT lithium-ion battery produces 280 percent of the total lifetime work and two to three more battery cycles than Ni-Cd batteries while weighing 40 percent less.

The new Bosch ultra-compact 10.8-volt Litheon IMPACTOR Fastening Driver (PS40-2) weighs a mere 2.2 pounds but delivers a staggering 800 inch-pounds of torque.

DeWalt’s Nano-Phosphate lithium-ion battery technology, available in 18-, 28- and 36-volt platforms, offers users the ability to match their tool’s performance to their applications and benefit from the ergonomic advantages of lithium. Nano-Phosphate lithium-ion batteries also deliver greater runtime and can be recharged up to 2,000 recharges. And they are reverse compatible; the new batteries will work in any DeWalt 18-volt tool made since 1996.

Milwaukee is so confident in the patent pending design of its V28 and V18 tools that it offers a “5 year or 2,000-Charge Warranty” on its lithium-ion manganese cell batteries.

“Each transition of battery technology has resulted in higher levels of productivity while typically reducing battery weight,” says Steve Tayler, vice president, assembly and aerospace, for Makita. “Tooling manufacturers will continue to attempt to appease ever-demanding users by offering lighter and more efficient battery platforms and we see this trend continuing into the future.”

As an example, Makita’s 18-volt LXT lithium-ion (3.0-Ah) batteries deliver 18-volt power in 12-volt weight, but that is the beginning of the story. Makita’s Rapid Optimum Charger can recharge LXT batteries in only 25 minutes. The charger and battery communicate throughout the charging process via built-in computer chips in each to maximize charge efficiency. The charger also uses “Active 3 Control” for current, thermal and voltage control, has a built-in fan to cool the battery and carries the Energy Star label for charging efficiency.

Featherweight body, heavyweight punch
How far can lithium-ion batteries go? No one knows.

“We definitely haven’t hit the power-to-weight wall yet,” says Edwin Bender, group product manager, cordless, at Bosch Power Tools. “Further advancements in battery and power train technology will allow power-to-weight ratios to increase in the future.”

But battery packs and chargers are just two components. Manufacturers are evaluating every aspect of their tools for untapped improvements.

“There is a movement in cordless power tools to ‘do more with less,’ ” says Steve Jenson, product manager, DeWalt cordless fastening tools. “Advances in lithium-ion technology have done a lot to increase power-to-weight ratios, but a cordless power tool is a combination of sub-systems including switch, motor, transmission, etc. — not just a battery. Manufacturers will continue to offer improvements in these areas to take size and weight out of tools.”

Durability
Part of Panasonic’s approach is to increase durability by decreasing moving parts. Two of its newest tools, the EY7540LN2L 1/4-inch impact driver and EY7541LN2L 1/2-inch impact wrench feature brushless motors. Panasonic claims this design doubles motor life, reduces heat and uses 20 percent less electricity compared to a conventional brush-type motor. That energy savings translates, Panasonic says, into 20 percent greater runtime per charge.

Both tools also feature electronic switch designs which are also claimed to outlast typical switches by two to one.

Milwaukee is investing heavily in both battery technology and power train enhancements to drive durability in its cordless impacts.

“The Milwaukee V18 model 0881-22 V18 1/4-inch Hex Impact Driver deploys a full-size motor and all-metal mechanism that delivers 1,400 inch-pounds of torque, the highest in the compact impact driver category,” says Rick Gray, director, cordless for Milwaukee Electric Tool. This combination of power and durability features allows professionals to complete more work in less time with a tool that can withstand jobsite abuse.”

Additional user-requested features of this tool include a built-in LED light for illuminating dark work spots, a fuel gauge on the battery pack to accurately display remaining run-time, an overmold handle that reduces operator hand fatigue and on-board bit storage for frequent bit changing.

The finesse factor
“What’s the good thing about impacts? They’re fast and powerful. What’s the bad thing? They’re fast and powerful,” says Doug Bock, group director for Panasonic Power Tools.

To address this mixed blessing, manufacturers are building more control options into their tools to expand the range of applications impacts can do and refine the level of finished work they can produce.

Leading this approach are Panasonic’s brushless motor impacts, the EY7540LN2L 1/4-inch impact driver and EY7541LN2L 1/2-inch impact wrench. These tools also feature three speeds with preset torque levels to provide users with levels of control previously unavailable in cordless impact tools. The EY7540LN2L impact driver delivers 240 inch-pounds of torque in low/soft mode, 665 inch-pounds in medium mode and 1,330 inch-pounds in high/hard mode.

In another unique “twist” on control, Panasonic’s award-winning EY7202GQW cordless impact driver features a digital clutch and three-speed motor combination that can virtually eliminate over-tightening or cam-out situations.

Users can functionally program the tool torque and depth for each application to make fast work of repetitive jobs. And if a screw stops just short of flush, a quick pull of the switch will then advance the screw either 1/4, 1/2 or 3/4 of a turn depending on the speed you are in.

“What Panasonic is building now is a digital cordless tool,” Bock says. “This marriage of the electronic and mechanical allows the user to marry the performance of the tool to the application he is doing. You can adjust the product to the situation you are in at any moment, which is a capability we feel no one else is offering.”

New applications
Thanks to such advancements in both power and programmability, cordless impact tools enjoy growing popularity in an ever broader range of industrial applications.

“Cordless impact tools are being adopted by more and more trades at a very fast rate as end-users discover the benefits of small size, fast output speed and no reactionary torque, compared to traditional drill/drivers used for fastening applications,” says DeWalt’s Jenson. “Additionally, the peak torque delivered by an impact tool is 2-3 times that of a drill/driver, making them ideal for tough fastening applications or where ‘cam-out’ is a problem.

“The ability to ‘cut the cord’ opens up many benefits, including portability and the ability to work in remote places,” he adds. “Also, not being tethered to a cord or air hose increases tool ‘dexterity’ and the ability to access tighter areas; not to mention the relief of not having to work around or step over cords or hoses.

In-plant advantages
Industrial workers are embracing cordless impact tools for five key reasons, says Makita’s Tayler.

• “Maneuverability: Cordless allows the freedom from being tethered to a fixed position allowing the operator to more comfortably perform a given function.

• “Quality Control: The reduction of air hoses minimize the risk of damaging an already-painted vehicle (within the transportation industry) and therefore lowers the number of vehicles needing to be touched up.

• “Safety: The absence of air hoses reduces the potential for worker injuries typically because they present trip-hazards on the factory floor.

• “Costs Associated with Production Changes: Utilizing cordless products in manufacturing (versus pneumatic tooling) also eliminates the need to reconfigure air supply when production lines change or are expanded. The need for mechanical work is then minimized.

• “Energy Consumption: Utilizing cordless tooling instead of pneumatic tooling will lower energy consumption as it relates to tool operation. According to various industry feedback, the cost of a typical cordless assembly tool will generally be recouped within 60-90 days due to the dramatically reduced energy consumption.”

A leaner, meaner future
With each new generation, cordless impact drivers and wrenches expand their menu of industrial applications. Will the factory of the future be powered mainly by cordless impact tools? If you’ve ever walked through a factory full of hissing, leaking airlines overhead, you might be inclined to like that idea very much.

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