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Handheld Grinders

June/July 2012

Grinding Has Just Been Improved

Power tools are called power tools for a reason – they’re powerful.

And for that same reason, they allow users to get whatever the job is done more quickly and efficiently. But just as they are quick and efficient, power tools also carry the potential to be dangerous. Even if used correctly, sometimes a user may find himself in trouble, and even more so if they’re used incorrectly.

Metabo is very much aware of this, and because of that, they’ve built their new brake-angle grinders – the 5-in. WEPBA14-125 Quick and the 6-in. WEPBA14-150 Quick, dubbed the Alphabet Grinders – with a number of features to make them safer and more user-friendly. And not only are the new Alphabet Grinders designed to be safer in trouble spots, but they also reduce the risk of long-term injury and increase the life of wear items on the grinder.

The foremost of the Alphabet Grinders’ safety features is a dead-man paddle-switch. If an operator loses control of either grinder, he just needs to let go of it. The grinding wheel would automatically stop within two seconds or less, says Terry Tuerk, Metabo’s product manager. When using a thin cutting wheel, the grinder will stop even faster – in one second or less.

This is an almost 80 percent improvement over typical grinders that stop in eight to 10 seconds.

“Safety is paramount,” elaborates Tuerk. “When using an angle grinder every day, kickback is the number one issue, especially with applications where operators are working in real tight quarters, reaching with the tools and doing everything you’re not supposed to do with them.

“And with a regular angle grinder with no brakes, if you turn it off, the wheel is still spinning down for eight to ten seconds. So, if I’m running that tool, and I just turn it off normally and put it on my bench, with that 8- to 10-second run-down time, there’s a possibility of somebody just brushing by and getting caught by the wheel.”

Another helpful feature included on the grinders is their auto balance feature. And although it’s not exactly a safety feature, it does offer certain health benefits to users in the long run.

“The auto-balance feature functions through a flange that has been added to the spindle of the grinder,” explains Tuerk. “This flange offsets the out-of-balance condition of the accessory on the grinder, creating a much more ergonomic and comfortable feel for the user, because there’s no vibration going back into their hands and arms.”

As a result of this, long-term users of the Alphabet Grinders don’t have to worry about work-related health disorders such as HAVS, Hand/Arm Vibration syndrome or White Finger Syndrome, says Tuerk.

“There are new regulations on vibration in power tools in Europe, but none yet in the U.S.,” he comments. “But I know that OSHA is looking at starting to investigate the amount of vibration in power tools, so Metabo is ahead of the game in that respect.

“This means that companies who are using these tools can also go to their workers compensation insurance provider, point out what they’re doing and try to push for a little bit of a lower rate on their insurance, [since the grinders reduce the risk of long-term injury].”

In addition to the Alphabet Grinders’ health and safety benefits, the fact that they don’t produce any vibration means that consumables on the tool last significantly longer. Tuerk specifies that the grinding disc on the tools themselves lasts between 50 and 100 percent longer than on tools without the auto-balance feature – possibly even longer depending on the grade of the wheel and the type of material being processed.

“Because of the auto balancer, you have a much more consistent load between the wheel and the metal. When grinding without the auto balancer, it actually creates a force on the wheel,” says Tuerk. “The auto balancer removes that force, which allows the wheel to stay in contact with the metal and the grinding disc to last longer.”

Removing vibration from the grinders also means that the carbon brushes in the electric motors are able to last longer, resulting in the grinders being able to run longer before needing routine maintenance – 50 to 100 percent longer, or more depending on the application.

“Other components of the tool, such as the bearings, are lasting longer, too,” adds Tuerk. “The auto-balance system ends up offering a lot of cost saving benefits.”

Two other notable features of the Alphabet Grinders are their safety slip clutch and Quick System, which are included on most of Metabo’s industrial small angle grinders. The safety-slip clutch, located on the front side of the grinder, automatically disengages the spindle from the drive motor if the metal being processed binds up onto the wheel, giving the operator a chance to correct the situation.

The other feature, Metabo’s Quick System, facilitates a wheel change without tools.

“You just turn off your grinder, and while it’s spinning down, you push the spindle lock button on the top of the gear housing,” explains Tuerk. “And then the spindle lock button engages into the top of the clutch, stopping the spindle and allowing the spindle nut – or what we call a quick nut – to release itself by a quarter-turn to half-turn.

“It’s a huge enhancement to productivity, because now a wheel change is no longer giving a guy an opportunity for a coffee break when he has to cross the shop to get a wrench from some toolbox.”

In addition to the WEPBA14-125 Quick and the WEPBA14-150 Quick Alphabet Grinders, Metabo has also introduced the W18LTX 4.0, an 18-volt cordless angle grinder with the world’s first 4.0 amp-hour battery system.

With its improved battery system, the new W18LTX 4.0 offers a 33 percent longer runtime over 3.0 amp-hour cordless grinders.

“The longer runtime really does make a cordless grinder a viable machine to have, say, in a service truck or on a job site,” comments Tuerk.

When it comes to power tools, Metabo wants to put more power in the users’ hands. But at the same time, however, they also want to keep users safe – features such as the dead-man paddle-switch on the Alphabet Grinders and the improved battery technology on the W18LTX 4.0 are examples of both aspects of this philosophy. And with research and development an ongoing project in the company, users can be sure that Metabo will continue to deliver safer and more powerful tools to them in the future.

Metabo