25 February 2000

Out on the cutting hedge

An electrically operated

flotation system and

improved arm geometry

number among the features

available on McConnels

latest Hy-Reach hedge cutter

range. Andy Moore reports

McCONNEL has chosen to mark its 65th anniversary by introducing a new generation of hedge cutters designed for contractors seeking high output and performance.

Available in either 5.51m or 6.51m reaches, the hedge cutters are available in two builds – a basic Superior version, or higher specification Supreme model.

Both models feature improved arm geometry to enable more accurate vertical hedge trimming to be performed, while arm build calls for a stronger tapered box section for improved weight distribution.

Standard arm specification includes a 100deg power slew, hydraulic breakaway, while a 1.2m wide multicut flailhead (1.5m optional) has the facility of reverse drive operation to clear blockages.

For attachment, non-telescopic 5.51m reach models are three point linkage mounted as standard, while the 6.51m telescopic arm machines are designed for subframe axle mounting.

Other improvements to the range include an oil cooler, and a "cleaner look" rear plastic guard with lighting board which can be swung open to provide access to main control valves.

Standard pump type comprises a 65hp independent gear driven model rated at 125lt/min, or a 75hp piston pump can be specified for higher 130lt/min outputs.

Geometry improvements aside, one of the main developments is to be found on the Supreme model. McConnel has now developed the Easy Drive System (EDS) – a system which automatically controls head and arm float to allow higher mowing speeds.

The system comprises two electrical sensors or potentiometers fitted inside two pivot points on the hedge cutters king post – the parallel linkage and the lift ram. The sensor in the parallel linkage pivot point monitors flail head movements by measuring the turning angle of the pin during operation, as does the sensor inside the lift ram pivot point.

Readings from both sensors are sent digitally to a CanBus system on the proportional control system inside the cab which, in turn, informs the hedgetrimmers hydraulic system how much ram pressure is required to allow the arm and flailhead to float over changing ground contours.

With readings taken every 30 milliseconds, pressure in the lift rams is altered very rapidly so the flailhead dose not bounce over ground contours. As a result, McConnel claims the hedge cutter can be operated at up to 19kph (12mph) forward speeds when verge mowing.

"Hedge cutters using conventional gas accumulator float systems have to be operated at nearly half these speeds due to a high level of bounce over ground contours," says Jack Brown of McConnel. "The EDS system provides much more accurate and responsive control over arm and flailhead float and will help to reduce operator fatigue due to the automatic operation."

Control of EDS is carried out using the systems own dedicated proportional control console fitted on the seat armrest inside the cab.

The console provides joystick control of arm movements, while two top buttons can be interchanged to enable operation of either arm power slew or telescopic rams.

In addition to the joystick, the console offers a touch pad which is used to control rotor start/stop/reverse functions and on/off control of head angle and lift float services.

If the operator moves the joystick while the floats are switched on, float automatically deactivates until the arm or head have been repositioned and the float is re-engaged a second later.

Prices for the Superior start at £11,815, while the higher specification Supreme model equipped with EDS rises to £19,910. &#42

McConnels latest range of Hy-Reach hedge cutters are available with 5.51 or

telescopic 6.51m reaches in two model designations – Superior and Supreme.