Power tool round-up

By Patrick Hill23 April 2008

Cordless drills feature electronics

Electronics in Makita's 3.2 kg BHR240 rotary hammer drill provide its variable speed control and safety braking, and enable its 18 V Li-ion batteries to be recharged in approximately 22 minutes.

The tool delivers 1.9 J of impact energy at up to 4000 blows/min, and the BHR240 can punch an 18 mm bit into concrete, drill 13 mm in steel, and drive a 26 mm auger bit in timber. Offering rotary-only, rotary with hammer action and hammer-only modes, it has a maximum, no-load speed of 1100 rpm.

It is also electronics in Bosch's new cordless drill, the 2.9 kg GBH 36 V-LI Compact Professional, that provide the commutation in its brushless, 36 V motor. Similar circuits prevent overheating of its lithium-ion battery packs, as well as display charge levels and temperature.

The tool features a pneumatic hammer mechanism, which generates an impact energy of 1.7 J. lt is the first Bosch cordless hammer drill with the company's Anti Vibration System, which combines a compression spring and flexible handle to reduce vibration to 10 m/s2, says the company.

Its drilling capability is 18 mm in concrete and 13 mm in steel, and the 1,3 A-hr battery pack enables drilling 100 holes (6 x 40 mm) into concrete on one charge. Price is approximately €500.

Mechanicals, not electrics, are meanwhile central to Bosch's redesigned cordless combi drills and drill drivers. At the heart of the range, called Turbo Tough, is a double-wound, 48 mm-diameter motor. It drives an all-metal, five-planet gear transmission, which is cooled by a fan-assisted air-cooling system. A progressive clutch allows fine torque settings.

Available in 18, 14.4, and 12 V versions, the tools have nickel-metal hydride batteries with cooling sticks to extend their life, as do their 12-point connections. Bosch designed the tools to be robust - they will withstand drops from a height of 2 m, says the company.

The 18 V version of the GSB combi drill weighs 3.0 kg and generates a maximum torque of 75 Nm, and Bosch says it optimized the series' gearbox ratio for hammer drilling. It has a second gear speed up to 31000 rpm. The 18 V version of the GSR drill driver, which weighs 2.7 kg, generates a maximum torque of 82 Nm.

Working rebar

"Practically maintenance free", says Multiquip, of its improved, single-phase, 115 V, portable reinforcing steel bender, the MB-25A, which bends rebar up to 2.5 cm in diameter. Other features include: push button start and stop; an electro-magnetic clutch; and a single control knob that selects the precise bending angle from 0 to 180º.

New rebar cutters from the California-based company are the HBC-19 and HBC-25, rated at 9 to 12 amps. They cut rebar up to 2.5 cm thick and at maximum cutting speeds from 3 to 9 seconds. The 21.7 kg HBC-25 heavy-duty unit cuts 2.5 cm materials in 4.5 seconds. It features a built-in hydraulic pump with magnetic particle filtering, and its blades can be easily rotated for increased service life.

From manufacturer Max in Japan is the RB655 rebar tie tool, which uses 1.5 mm wire to single-strand tie bar up to 65 mm in diameter. Now available in the UK from distributor Young Black, the tool uses an innovative reverse motor mechanism for tighter, consistent ties with a minimum of wire waste, says the company. It makes a slash tie in less than one second and uses reels of wire that are smaller than the 25 kg rolls used for hand tying.

Powerful hammers

Makita has extended the lower end of its corded rotary hammer drill range with two new models. The bigger is the 8 kg 4511C, which Makita says has double the impact power of its predecessor while reducing vibration by more than 50% - to 7.5 m/s2 in rotary hammer mode and to 7.0 m/s2 in hammer-only breaking mode.

The 4511C's 1350 W motor generates 13 J of impact energy. At up to 2750 blows per minute, the tool will drive a 45 mm drill bit or 125 mm core bit into concrete and masonry. It has a no-load speed of 130 to 280 rpm.

The 5 kg HR3210C model has an 850 W motor and generates 6.4 J at up to 3300 blows/min. It can punch a 32 mm hole into concrete and drive a 90 mm CT core cutter. This 3-mode machine provides rotary-only operation for drilling at speeds between 315 and 630 rpm at no load.

The HR3210C features Makita's 2-Mass fulcrum-hinged, rear grip handle and a vibration damping side handle for a rating of just 7.5 m/s2 in hammer mode and 10 m/s2 in drilling mode. Both the HR3210C and the 4511C are double insulated and have Makita's torque limiter system.

DeWalt's new, heavy-duty D25901K and D25941K demolition hammers employ electronics to start softly on contact and to maintain optimum performance under load, says the company. Circuits also give the D25901K a 19-setting, variable impact control.

A 14 A motor gives the D25901K 25,5 J of impact energy, while a 15 A motor generates 29,8 J of impact energy in the D25941K offers. Both models have active vibration control, using floating handles and counter balance mechanisms, as well as a one-step adjustable, 12-position chisel rotation feature.

New Product Highlights

Hilti's PD 4 distance measuring tool uses laser technology to measure distances up to 70 m. Measured distances appears on the display in a fraction of a second, and the previous two measurements also remain visible.

The new Makita HK1820 hammer action scraper delivers up to 3.9 J of energy at 3200 blows/min to drive wide scaling chisels or bull point steels. The 3.3 kg tool has a vibration rating of 10 m/s2.

Electronics recharge the 36 V lithium-ion batteries of Hilti's new WSR 36-A cordless reciprocating saw in 28 minutes.

Makita's new 3601 B "D" handle router features an "American style", one-hand operation design for use when extensive edge profiling is required. The 3.5 kg, non-plunge tool has a ½ " collet capacity for all long-shank routers, a no load speed up to 23000 rpm and a maximum throat depth of 30 mm. It is powered by a 930 W motor available in 110 V or 240 V variants.

The NT65GS cordless nailer from Hitachi accepts straight finish nails of 16-gauge in lengths from 25 to 65 mm. Two 1.5 Ah, 3.6 V Li-ion batteries power the 1.8 kg tool and re-energise in 60 minutes from a charger with a cigarette lighter, as well as a mains, lead. The tool features a 100-nail capacity magazine, tool-free depth adjustment and jam clearance, and dry firing lockout. Price is €375.

Bosch has added the GKS 36V-Li circular saw to its cordless, 36 V lithium-ion range. The 4.7 kg saw cuts up to 30% faster than the company's 24 V equivalent, and up to 70 m of particleboard can be cut with one battery charge. With an upper guard and footplate of die cast aluminium, the tool is 419 mm in length and 276 mm high. Its price is €600.

Husqvarna's new, 25 kg electric wall saw, the WS 440 HF, is its first-ever electric model and delivers 13 kW of power to the blade shaft. A variable speed transmission allows optimal speeds for combinations of blade diameter, type, and work material. Rotation direction is selectable, meaning the water spray can be controlled independently of operator position. The saw, available in Europe, is based upon the Swedish company's hydraulic models and has quick fastening and radial attachment features.

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