Adj 4.15 Knife Cushion Adjustment - Challenge CMT-130TC Service Manual

ADJ 4.15 Knife Cushion Adjustment

The knife cushion value sets the amount of
"cushion" that the hydraulic system exhibits near
the bottom of a cut cycle. This cushion creates
a smooth transition between the downward and
upward movement of the cutting mechanism at
the bottom of a cut. Too little cushion, and the
cutting mechanism will jerk and/or bang when
changing directions. Too much cushion, and the
cutting mechanism will take too long to travel
down causing a time-out error.
Initial Actions
Make sure hydraulic pressures are set correctly
(ADJ 4.13 Hydraulic System Pressure and ADJ
4.14 Counterbalance Valve).
Procedure
1. Switch the main power ON and press the
"Setup" button to bring up the setup options.
2. Press the "Service Info" tab to open the Ser-
vice Info screen (Figure 4-30). Click on the
"Enable Tabs Code" text box, enter in the
code 6125 and press enter. This will unlock
all of the locked tabs.
3. Press the "Hydraulic/Air" tab to open the Hy-
draulic/Air screen.
4. Press the green start button.
5. The screen should now look similar to either
Figure 4-31 or Figure 4-32, depending on
software version of trimmer. Does the
screen have a "Calibrate Hydraulics" button
like the one shown in Figure 4-32?
Y N
Move the knife cushion slide bar until the
cushion value is approximately set to 185.
Now skip to step 7.
4. Repair/Adjustment Procedures
6. Press the "Calibrate Hydraulics" button, and
then press the green start button. The trim-
mer will run through a brief procedure to de-
termine the best initial setting for the knife
cushion value.
7. Press the "Enable Cut Cycle" button.
8. Press the green start button to initiate a cut
cycle. Repeat this a few times and observe
the knife at the bottom of the cycle. If it
slows down too much, slide the scale key to
the right to decrease the cushion and in-
crease speed of the cycle. If it bangs or jerks
too much, slide the scale key to the left to in-
crease the cushion and decrease speed of
the cycle.
9. When finished, press the "Save and Exit"
button.
Figure 4-30. Service Info Screen
MAY 2019
4-20
Figure 4-31. Knife Cushion Setting
(08-06-2018 version software and earlier)
Figure 4-32. Knife Cushion Setting
(02-28-2019 version software and later)
CMT-130TC Book Trimmer