29
USER MANUAL
TRACTOR FRONT DISC MOWER
ALPINA / SAMBA F
5.7.
Operation
Dear User,
If this is your first experience with a disc mower (e.g. you have mowed with a twin-drum deck so
far), you require some essential trivia:
1.
The biggest advantage of disc mowers is approximately 20 % reduction of input power, low
inertia of ramping, and large cutting widths.
2.
A certain disadvantage is a rougher and rolling-like stubble (which can be seen with the swath
collected), especially when mowing laying grass. You can mow the grass with the mower deck
in level to ensure a level cut of the stubble; still, the aesthetic quality will be inferior to that
provided by a twin or quad-drum mower, since the blades run in parallel to the ground. This
causes the laying grass to bend down from the air blast and rise again once the mowing area
has been cut, resulting in an uneven appearance.
3.
Every disc mower can leave small patches of uncut grass blades if the mower blades move
down the grass lay. This is normal. The disc mowers theoretically and practically cannot provide
a cut quality of the stubble equal to that provided by twin-drum mowers; the blades work in
parallel to a level plane or up to 3° of forward tilt, whereas twin and quad
-drum mowers cut at a
steeper angle (up to 23°) to the ground.
4.
Despite these minor drawbacks, disc mowers have been increasingly popular with the farmers
around the world. Thanks to the state-of-the-art manufacturing, the modern disc mowers can
enjoy a very long service life (of up to 1000 % of a typical drum mower).
5.7.1.
Basic mowing performance guide
Optimum operating settings
1. Forward tilt: 0° to 3°, i.e. 4.5 to 6 cm of cutting height.
2. Operating ground speed V ≥ 10 km/h.
3. ALPINA mower PTO speed: 510 to 540 rpm (SAMBA F mower PTO speed: 900 to 1000 rpm). Higher
PTO speeds may result in uncut patches between the mowing discs.
Tall or laying grass
5. Increase the forward tilt to provide a cutting height H = ca. 4.5 cm.
6. Operation with the mower deck held level will cause the grass blades to twist around the material
ejection drums.
7.
Increase the operating ground speed to V ≥ 12 km/h. (The sooner the better.)
8. Do not turn or reverse before leaving the mowing area.
-
The optimum forward tilt angle of the mower deck is 0° to 3° from the ground. Any tilt above 3° may
result in small uncut patches within the stubble. This will slightly reduce the aesthetic finish of the
stubble; however, the impact on the mower performance will be negligible. Any backward tilt of the
mower deck will significantly reduce the mowing performance; in extreme circumstances, the mower
will not engage and cut the material. The mower deck and the skids can be damaged.
- If the mowing area is predominantly tall grass, the first and second swath should cut by 6-7 cm. If the
mowing areas is predominantly low grass, reduce to 5 cm. The last swath should be a bit taller, 7-7.5
cm above the ground.
- A tractor PTO speed too high will cause strong air turbulence around the rotating mowing discs and
significantly reduce the mowing performance.