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Executive Report: Breaking new ground Phil Mist, EHN’s power tools specialist, puts DeWalt’s new 30kg breaker through its paces and finds it to be an impressive performer. Having to use almost any brand of T-shaped breaker for a prolonged period is not something I personally relish, but it is an essential tool for the construction industry. Any such machine must enable high productivity while protecting the operator from the worst effects of HAV and noise. Due to advances made in materials and design, most power tools now entering the market are not only more efficient, but are also much more user friendly. The new D25980 30kg breaker from DeWalt is an excellent example. It has a very powerful 2000watt motor and, despite being heavily overloaded for long periods during testing, it never missed a beat - eventually smashing asunder a large block of 45Nm concrete that has spent the last few months in my yard. The tool’s single energy blow rating is said to be 68J, which is about the same as several other models on the market. Whilst it quickly smashed the block of concrete, the impact energy was not particularly noticeable because of the low vibration emissions. The impact speed is 900bpm, almost one third less than the fastest machine available in the UK, the Kango 2500, which operates at 1400bpm. This perhaps explains the reason for the high blow energy. The D25980 actually weighs 31kg without a chisel, similar to its competitors. It has a 28mm hexagon tool holder (some other machines have the same size of hexagon front end, and some the larger 32mm configuration), and it accepts all types of 28mm hexagon chisels and points currently available on the market, whether they have a flange or not. Low tri-axial figure What is most surprising is the D25980’s tri-axial vibration figure of 6.6m/s2. This extremely low figure is said to allow an operator to use it for a maximum of 4.35 hours and remain within permitted exposure levels. To achieve this, it has been necessary to build into the tool suspended, or floating, handles that rotate when pressure is exerted downwards. If the operator continues to press down after the handles reach their final stop position, vibration emissions obviously increase, but the rate of penetration of the concrete does not. Even a totally inexperienced operator will soon realise that applying extra pressure is unnecessary. A rubber covering on the handles themselves enhances user comfort. Obviously, rubber inserts or covers do not eliminate vibration, but they do help reduce the worse excesses. DeWalt’s own anti-vibration system, previously only available in its 7kg and 9kg models, is also incorporated and, even under extreme pressure, it works really well. Full electronic speed control is included (the D25980 is said to be the only T-shaped breaker on the market with this) and the total package results in a machine with amazing performance. In prolonged breaking tests it substantially outperformed a number of other models, and one machine by more than 50%. The overall height or length is similar to other models and the tool is suitable for users of any height. If an operator is particularly tall, and the machine and chisel combination is too short, he may have to bend more and risk back strain. I am nearly 2m tall but felt no ill effects from using the D25980 for extended periods, nor did I suffer from prolonged tingling in my hands after the test, suggesting that the anti-vibration technology works well. The new D25980 breaker can be supplied with a trolley for manoeuvrability around construction sites, and this is an essential requirement for many users. Indeed, the level of thought that has gone into the design of DeWalt’s new 30kg breaker has resulted in a tool that is definitely fit for purpose. Whether it will pass the test of time is something that will be looked at in the next few months, but from a performance point of view it certainly does the job. • T
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339258 Executive Hire News › Archives › November 2006 › Executive Report › Breaking new ground
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