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Market Report: Power Tools & Accessories Revolutionary technology Phil Mist is impressed by the performance of Hilti’s latest hammer drill and the new technology that the manufacturer has incorporated in it. Almost exactly 40 years ago, Hilti launched the TE 17, its first electro-pneumatic hammer drill. I remember it well, and I must own up to having used one on many occasions. In 1967 the TE 17 was a revolutionary concept and many of its features are now common in other tools. Modern machines, of course, benefit from improved technology not even thought of then, and Hilti’s latest offering, the TE 40-AVR rotary demolition hammer, is again somewhat revolutionary. It is from a new family of hammer drills and demolition hammers which, when looked at sideways, appear to be leaning towards the material being drilled, as if eager to start drilling or breaking immediately. Appearances are not always to be believed, but this tool certainly looks businesslike. Power comes from a 1010watt motor and this, together with a single blow energy rating of 4.9J and an operating speed of 0-550rpm, produces a penetration rate as good as anything previously available in the UK, and certainly one that is better than most of its competitors. A hammering rate of up to 3,180bpm, allied to its single blow rating, results in a quoted tri-axial vibration level of 10m/s2 in ‘real-life’ testing. This figure might appear a little high to some, but it depends how you interpret it. Despite the debate on HAV that EHN has monitored in recent years, there is still confusion in some quarters about what the readings mean in practice. It can be more meaningful to quote the amount of work that can be achieved (an approach pioneered by Hilti). The TE 40-AVR can drill up to 70 holes of 20mm diameter in medium-hard concrete before the operator reaches the exposure action level (EAV) under the Control of Vibration at Work Regulations, and almost 290 holes before attaining the exposure limit value (ELV) limit. Of course, an operator drilling this number of holes should ideally have assistance from a second, or even third, operator to enable him or her to have suitable rest periods. Vibration reduction system The machine incorporates Hilti’s AVR (Anti Vibration Reduction) system, which suppresses the worst effects of vibration caused by the sheer efficiency of the hammer mechanism. The more power tool designers boost performance, the more vibration is generated, so further steps must be taken to dampen it. The TE 40-AVR also has the manufacturer’s patented Theft Protection System (TPS) which, when activated, renders the machine inoperable for anyone except the registered owner. The tool’s maximum drilling capacity in concrete is 32mm but its best performance is claimed to be when drilling holes of 14-24mm. It can also drill up to 13mm in steel using the rotary-only drilling setting, and also performs well when light chiselling in hammer-only mode. The selector switch, which is positioned on the left hand side, as on most other demolition hammers, takes a little getting used to, even though it looks simple to operate. It has four positions, namely the standard rotary hammer and rotary drilling positions, and a 360° setting for obtaining the optimum angle of a chisel before setting the machine to the fourth position, hammer-only (rotation stop), for chiselling work. Weighing only 6kg including its side handle (Hilti claims 5.5kg), the TE40-AVR is certainly light enough for use over long periods, due to the AVR system and a totally de-coupled rear handle that is completely isolated from the main part of the machine. This also facilitates extended operation. The tool has a 360° rubber front handle giving excellent operator control and comfort, and the rear handle incorporates a large ‘dead man’s’ on/off switch without any lock-on facility. Well engineered The front tool holder is an SDS Plus fitting and can be easily removed by pulling forward on the collar and pulling the entire assembly off the spindle. A well engineered keyless chuck that can be fitted in seconds is available for operators wishing to drill wood or steel. During EHN’s tests, a number of 32mm diameter holes were successfully drilled in hardwood with a decent quality auger bit. The mechanical clutch system cut in on several occasions when the machine was put under heavy load, and also when drilling 24mm diameter holes in hard concrete. The balance between saving an operator from a sprained wrist and the clutch activating too often, and therefore reducing performance, is difficult to achieve, but Hilti’s engineers seem to have done so. Placed at the rear left hand side of the motor body is a service light indicating when servicing is necessary. The tool also benefits from Hilti’s two-year no-cost service and repair system, which includes the collection and return of the machine, a lifetime warranty and a lifetime repair cost limit after the first two years. It represents an impressive package and, overall, the TE 40-AVR is a very efficient, well balanced drilling and breaking tool that is a delight to use. • T
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1000 Executive Hire News › Archives › July 2007 › Market Report › Revolutionary technology
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