Bio-Rad PDQuest 2-D Analysis Software - Manual (Page 53)

2. With one hand, hold the lower part of the Spindle Cutting Assembly. With the other,
Adjust the height of the silver cutting shaft by moving the shaft up or down as
required.
3. After adjustment, tighten the set screw to "snug" but do not overtighten. Damage
can occur to the cutting shaft if the set screw is overtightened. The set screw must
be tightened before a test cut is made at the new height.
4. When the tip depth looks correct, use the software command "Raise tip" and then
"Test Cut" to test the cutting depth. A wetted piece of PVDF membrane on the
platform works well for this test.
5. If the shaft will not go any further but the cutting tip still needs to be raised, the
carriage needs to adjusted. Use the following procedure to adjust the cutting
carriage.
Note: It is important to adjust the cutting tip height to the correct position for best pick-up
efficiency, especially when using gels on a backing. When using backed gels, make sure that the
cutting tip is going down far enough to lightly score the cutting sheet, but not going too deep. If
the cutting tip is set too deep, the tip will not slide across the backing and will not be able to
dislodge the gel piece from the backing. You can see the cutting head assembly move back and
forth. If the tip is stuck in the cutting mat, it will not move and the shaft will flex back and forth. If
you see this result, raise the cutting tip height.
7.5 Adjusting the Cutting Carriage
1. Turn OFF the spot cutter instrument.
2. Remove the black Cutting Head Cover.
3. Remove the spindle belt, as in diagram 1.
4. Unscrew the ground cable connecting the cutting head to the mounting plate.
5. Remove the spindle cutting assembly by removing the two mounting screws. See
diagram 2.
6. Unscrew the two hexagonal screws holding the carriage cover, remove cover. See
diagram 2.
7. Loosen the 4 screws fixing the carriage. These are screwed in very tightly to ensure that
the mechanism does not change position after adjustment. See diagram 3.
8. Adjust the height as required.
9. Tighten the 4 screws.
10. Place the carriage cover back into position.
11. Mount the cutting assembly using the two screws.
12. Replace the grounding cable, belt, and spindle cover.
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