Challenge SPARTAN 150 M, Technical Service And Parts Manual

Page: 13 / 42

3.0 Maintenance Guide
12
4. With the squaring screws tight, make another test. Continue to adjust and test until no trim
occurs when testing either sequence.
Note: Once the backgauge is square, check the backgauge accuracy (see section 3.4.2 ) to make
sure it is accurate.
3.4.2 Backgauge Accuracy Adjustment
If the backgauge position readout does not match the actual measurement between the knife and the
backgauge, the accuracy can be adjusted. The accuracy can be checked by the following procedure:
NOTE: The backgauge should be squared before attempting to adjust the accuracy. (See Section
3.4.1 Squaring the Backgauge, page 11.)
1. Place a 1/4 to 1/2” lift of 8-1/2 x 11 “ paper against the center of the backgauge.
2. Using the backgauge position readout, bring the lift up to the 10.00” position and make a cut.
Then move the backgauge up to 5.00” and make another cut.
3. Take a sheet from the center of each lift and compare them to each other. The cutter will
always space accurately between cuts (in this case the 10” and 5” cuts) whether the overall
accuracy is correct of not (Figure 8). The front stack will be a true 5”, but the paper left
against the backgauge will not be if the backgauge position is inaccurate.
Figure 8
4. The backgauge accuracy can be corrected by adjusting the preset screw attached to the
bottom of the backgauge nut assembly (Figure 9). Disconnect the power cord. With the top
cover ON, place the machine on a flat level surface on it’s left side. Place a 5/16” wrench in
the preset screw and hold in position while loosening the jam nut. Adjust the screw as
follows:
•
If test pile is short (back pile is less than 5”), turn screw out (counterclockwise).
•
If test pile is long (back pile is more than 5”), turn screw in (clockwise).
1/4 turn = .010” backgauge adjustment
1/3 turn = .014” (9/64”)
Questionable Accurate