Power tools drive productivity
24 July 2012
Power tools are meant to supplement, even eliminate most handtool operations and the performance and versatility of modern power tools continues to make tasks more efficient and less of a burden.
The key development over the previous decades has been the improvement in the performance, longevity and capacity of cordless power tools. Mains-powered drills, planers and grinders made significant improvements in productivity in the early days and this led to powered screwdrivers, saws and sanders.
For electrical installers, the performance and size of power tools is especially important. Whilst the percussion and hammer functions were developed for mains tools, there was a new philosophy about to emerge.
With the usage and expectations of power tools growing, the restricted movement and access limited by the hindrance of the power lead encouraged the use of battery power and the first applications featured Ni-Cad as the cell material to hold the energy. The introduction of cordless tools was a revolution to all trades and naturally the demand was immediate for greater drilling power and longer charge life.
The quest was always to attain the level of performance for a battery-powered tool that was provided by a mains-powered AC device and battery technology has been a major factor in this quest. Ni-Cad still serves well as a simple, inexpensive cell material but there are downsides such as safe disposal and the charging limit where the battery takes on a memory of partial charge if it is not fully discharged before recharging takes place. Size and weight are also limitations as power demand grows. However, Nickel Metal Hydride (Ni-MH) removes the memory problem, speeds-up the charge time and delivers more power for the same physical capacity. And in recent years, Lithium-Ion has grown in popularity so that now it is currently the key battery cell material.
Lithium-Ion (Li-ion) is certainly a revolutionary battery technology. Long-lasting Li-ion cells are 40% lighter than a similar Ni-MH cell which is significant in the higher weight, higher capacity tools used by tradesmen. This new high-density cell material provides 430% more working capacity during the lifetime of the cell. Li-ion will also accept faster charging and has therefore quickly become the power source for professional power tools.
Whilst productivity is vital, operator safety is a paramount consideration in the design of machines and in their safe operation. In recent years the industry has focussed on the risk of HAV, (hand arm vibration); the painful result of using high-powered tools where the constant vibration is transferred to the operator’s body through the handles of the machine.
Several years ago, Makita introduced AVT, an Anti Vibration Technology system built into the larger, heavy-duty hammer drills. It uses the air pressure generated by the piston movement within the machine body to move a counter balance in the opposite direction to the impact movement, thus dampening out the vibration effect of the piston hitting the drill steel. Whilst this cuts the potential vibration that could be transferred through the machine to the operator, it actually improves the impact performance of the tool. As such, AVT technology has recently been applied to reciprocating saws, breakers and outdoor power equipment.
For high-powered rotating equipment such as grinders, the soft-start system controls the motor speed from start-up so that even if the trigger is squeezed fully open from standstill, the motor builds-up speed slowly. This means that the torque loading does not try to pull the machine out of the hands of the operator.
For the electrical tradesmen, the size of tools is always going to be important. Getting drilling power into tight spaces is a regular problem but the recent introduction of 10.8v cordless tools is a bonus. These are physically small but are high in power. Typically, a 10.8v impact driver will generate around 90Nm of torque and up to 3000 impacts per minute, but weighs less than 1kg.
Power tool design continues to evolve, with more performance and smaller dimensions being the main criteria. For the professional tradesmen, tools are an investment to earn wages. Buying the best you can afford is the correct policy.
Kevin Brannigan, Marketing Manager, Makita UK
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