MacDon R80 Rotary Disc Pull-Type Windrower - Manual (Page 46)

OPERATION
Form # 169053
44
Model Year - 2009
6.13.4 Roll Gap and Timing
Steel rolls "condition" the crop by crimping and
crushing the stem in several places. This allows
moisture release for quicker drying. The degree
to which the crop is conditioned as it passes
through the rolls is controlled by roll gap. See
illustration. The gap is factory set at 1/4 inch (6
mm).
Correct conditioning of alfalfa, clover and other
legumes is usually indicated when 90% of the
stems show cracking, but no more than 5% of
the leaves are damaged. Use only enough roll
gap to achieve this result.
A gap up to 1 inch (25 mm) may be desirable in
thick stemmed cane-type crops; however, too
large a gap may cause feeding problems.
Grass type crops may require a smaller gap for
proper feeding and conditioning.
IMPORTANT
When the roll gap is decreased, the roll
timing is critical because:
• conditioning is affected, and
• the bars may contact each other.
6.13.4.1 Roll Gap Adjustment
DANGER
Stop engine and remove key from ignition
before leaving operator's seat for any
reason. A child or even a pet could engage
an idling machine.
a. Lower header fully.
b. Loosen and back-off upper jam nut (A), both
sides of conditioner.
c. To increase roll gap, turn lower nut (B) clockwise
which raises the upper roll.
NOTE
The amount of thread protruding through
jam nut should equal roll gap. Factory
setting is 1/4 in. (6 mm).
NOTE
When adjusting roll gap, be sure that the
thread protrusion is the same on both
sides of the conditioner roll to achieve
consistent intermesh across the rolls.
d. To decrease roll gap, turn lower nut (B)
counterclockwise which lowers the upper roll.
e. Tighten jam nuts (A), both sides.
f. Inspect roll gap at both ends of the rolls at
access port (C).
ROLL GAP
CROP
C
ROLL GAP
0.25 in. (6 mm)
A
B