Alamo 7191852C - Manual (Page 74)

OPERATION
PA91 02/08 Operation Section 4-22
© 2009 Alamo Group Inc.
OPERA
T
ION
7.3 Forward Speed
Tractor ground speed is determined by common sense and experience. It should be slow enough to allow
sufficient time for the flails to cut the work without overloading. It is obviously better to make a second pass or
more in heavier growth to avoid undue strain.
7.4 Tractor Position
The position of the tractor in relation to the hedgerow will again be determined by experience. For a normal
straight forward hedgerow the position should be such as to allow the reach ram to be in mid-stroke. This
effectively allows the reach to be adjusted in either direction without altering the tractor’s position.
7.5 Operating Speed
The flail head should be run at a speed no higher than is needed to make a clean cut with no fall off in rotor
speed. This also allows better control of the tractor and reduces the tendency of the operator to “ride the clutch
pedal”.The recommended rotor speed is 2500 RPM.To achieve these speeds it will be necessary to run the
tractor engine to give a PTO speed of 450 RPM.
Never exceed 540 RPM on the PTO shaft.
7.6 Working Close In and High
When attempting to position the flail head to cut close in and high the main arm may touch against the stop
before the required head position is achieved. If this occurs select “Reach out”, this will cause the main arm to
lift off the stop allowing the “Lift up” motion to be continued on service selection.
By the use of this technique it is possible to position the flail head in the close in position from ground level to
full height.
7.7 Breakaway
The pivoted arm is held rigid and in line by the oil pressure in the fully extended breakaway ram. When the flail
head meets an obstruction and the tractor continues to move forward, oil pressure will build up against a relief
valve situated in the base of the breakaway ram. When the preset pressure is reached the valve will blow and
the oil will be vented into the lift ram. This will allow the flail head to pivot backwards and at the same time
cause the arms to rise. When the obstruction is cleared, oil pressure contained in the lift ram will cause the arm
and flail head to the work position.
7.8 Wire Trap
The flail hood is equipped with a wire trap. The trap consists of a steel plate welded across the underside. Any
loose ends of wire which are picked up and carried round by the rotor are cut by the edge of the metal plate
and fall harmlessly to the ground. This plate should not be interfered with or modified in any way.
Furthermore, this wire trap does not relieve the operator of the responsibility of checking and cleaning the flail
when it is suspected that wire has caught in the rotor.