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Executive Report: “Simply stunning” Phil Mist, EHN’s power tools specialist, believes that the latest cordless Lithium-Ion products, such as DeWalt’s new launches, are worthy of consideration for hirers’ fleets. Until now, it has been almost automatically accepted that mains powered electric tools were more powerful than battery powered or cordless equivalents. However, modern 36V Lithium-Ion tools can perform every bit as well, so that many arguments for using 110V tools and a transformer on construction sites no longer seem relevant. The available power is simply stunning, and even though they are often rather large, Lithium-Ion batteries weigh little more than many other types and capacities of battery. Consequently, these tools have an unrivalled power to weight ratio and compare favourably with mains electric versions. Providing they are well balanced, operators soon get used to the extra size and slight weight increase, and their flexibility in use makes such cordless equipment worthy of hire fleet buyers’ attention. DeWalt recently launched an entire family of such machines. Pride of place goes to the new 36V SDS Plus hammer drill, model DC232, which has settings of rotary hammer and rotary only. With electronic speed control providing a range of 0-1,150rpm no-load speed and 0-850rpm under full load, it packs a powerful punch of 2.5 joules of single blow energy. Having a maximum drilling capacity of 24mm in concrete, its power to weight ratio is comparable with that of many mains powered machines. Weighing only 3.7kg including the battery, and with a front handle and depth rod for operator control, the tool is simple to use and immensely powerful. The noise emissions of 82dB(A) (sound pressure) and 96dB(A) (sound power) are not dissimilar to mains powered tools, and the tool’s vibration emissions of 8.2m/s2 are not excessive. A removable front end drill holder allows a good quality drilling chuck to be fitted for both rotary only drilling into wood and steel, and for driving screws. The DC234 is a three-mode version with an additional hammer-only setting for light chiselling. Also new is the DC900 combi drill driver which has a three-speed gearbox. Operating speeds of 0-400rpm, 0-1,200rpm and 0-2,720rpm permit a whole range of applications and the drilling of many materials in a variety of sizes with a maximum diameter of 13mm in steel. Impact rates of 0-7,650bpm, 0-20,400bpm and 0-27,200bpm provide drilling speeds suitable for masonry and light concrete up to 16mm in diameter. The product has a high quality drill chuck and a spindle lock for easier bit changing. The claimed maximum torque is 40Nm, and although I was unable to confirm this during hands-on testing, this seems reasonable based on the power available during heavy drilling. The
DC900
weighs
only
3.1kg
including
battery,
compared
to
another
well
known
18V
cordless
combi
which
weighs
in
at
2.7kg.
The
charger
supplied
takes
a
full
60
minutes
to
charge
the
battery
from
empty
but
has
the
ability
to
retain
full
performance
using
an
auto-refresh
mode,
balancing
the
charging
capacity
of
the
cells.
The
noise
emissions
of
103dB(A)
(sound
power)
and
94dB(A)
Perhaps DeWalt’s most surprising new tool is the DC300 circular saw. Thirty years ago, mains powered 71/2 in diameter machines were powered by motors of around 1,010watts (input wattage), and although this may look unimpressive today, they did have a good power to weight ratio and cut timber efficiently. This new tool is a step up from the original Trim Saw and provides the equivalent of 940watt output power. How things have progressed! The cutting speed is 4,000rpm, and the 184mm diameter blade (20mm bore) gives a 62mm maximum depth of cut. Weighing 4.7kg including battery, the DC300 is quite a beast. It has noise emissions of 105dB(A) (sound power) and 94dB(A) (sound pressure) and a surprisingly low vibration level of 1m/s2 when measured using EN50144, or 1.8m/s2 when using EN60745. This could be confusing, and shows the need for consistency amongst manufacturers when quoting vibration figures. Almost as astonishing in performance is the new DC305 reciprocating saw. With a claimed maximum output power of 710watts and a no-load cutting speed of 0-3,000rpm, it can cut almost anything. It has a 28.5mm stroke length and a three position sole plate or shoe. Weighing only 3.7kg, the tool is well balanced and a delight to use. It has a noise level of only 86dB(A) (sound pressure) and 95dB(A) (sound power) and a surprisingly low quoted vibration level of 2.7m/s2. With a tool-free clamping system, the blade can be inserted in all four directions for ease of use. It has a lock-off safety switch and a no-load operating speed of 0-3,000rpm, and is attractive for hire as an alternative to mains powered saws. Its Lithium-Ion battery offers a vast reservoir of power, making it well suited for heavy duty use, and this holds equally true for the other tools. • T
0700
4339258 Executive Hire News › Archives › May 2007 › Executive Report › "Simply stunning"
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