MacDon FD75 OM - Manual (Page 164)

OPERATION
4.7.8 Knife Speed
The header knife drive is driven by the adapter hydraulic pump which is driven by the combine feeder house. There
is no separate adjustment to control the knife speed.
IMPORTANT:
For variable speed feeder houses, the values
in the table are the MINIMUM feeder house
speeds.
Reduce the flow to the knife drive
motor if operating above these values to prevent
over-speeding the knife and knife failure.
Combine
Feeder House Speed
(rpm)
John Deere 490
CIH 575
Gleaner 624
Massey 624
Challenger 624
New Holland 575
Lexion 2 420
IMPORTANT:
Check that the knife speed is within the values in
the Table. Refer to
Checking Knife Speed, page
151 .
Table 4.6
Recommended Knife Drive
Speed Range (rpm)
Header Size
SKD DKD
30 ft 600–700 —
35 ft 550–650 —
40 ft 525–600 550–700
45 ft — 550–700
2. 420 is the rear shaft speed on Lexion combines (speed shown on cab monitor will also be 420). The output shaft speed is
actually 750 rpm.
169894 150 Revision A