MacDon FD75 OM - Manual (Page 160)

OPERATION
Controlling Header Angle
The header/guard angle is changed by adjusting the length of the center-link between the combine adapter and
the header.
The header/guard angle is controlled from the combine cab
with a switch on the operator’s control console, and an
indicator on the center-link.
Set the header angle according to the type and condition
of crop, and soil conditions. Use a lower angle setting (‘A’
on the indicator) for normal cutting conditions and wet soil
to reduce soil build-up at the cutterbar. Also lower angle
settings minimize damage to the knife in stony fields.
Use steeper settings (‘D’ on the indicator) for crops that
have lodged or are close to the ground, such as soybeans.
Figure 4.219: Center-Link
The shallowest angle “A” (center-link fully retracted)
provides highest stubble when cutting on the ground.
The steepest angle “D” (center-link fully extended) provides
lowest stubble when cutting on the ground.
Choose an angle that maximizes performance for your
crop and field conditions. The table below summarizes the
adjustment range:
Table 4.5 FD75 Header Angle
Header Size Guard Angle
30–45 ft. 2.0°–7.4°
Refer to 4.6.2 Header Settings, page 47 for recommended
header/guard angle settings for your particular crop
conditions.
Figure 4.220: Guard Angles
4.7.5 Reel Speed
Reel speed is one of the factors that determines the manner in which the crop is moved from the cutterbar
onto the drapers..
The reel performs best when it appears to be driven by the ground. It should move the cut crop evenly through the
cutterbar and onto the drapers without bunching and with minimal disturbance.
In standing crop, reel speed should be slightly higher than or equal to ground speed.
In flattened crop or a crop that is leaning away from the cutterbar the reel speed needs to be higher than the ground
speed, either by increasing the reel speed or decreasing the ground speed.
Excessive shattering of grain heads or crop loss over the header backtube may be indications that the reel speed is
too high. Excessive reel speed also increases wear of reel components and overloads the reel drive.
Lower reel speeds can be used with 9-bat reels which is an advantage in shatter prone crops.
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