Roland GR-640 User Manual page 78

Slide the material to place its left edge over the
grit roller.
At this point, check that the right edge of the material remains over the grit
roller on the right edge.
Straighten the material.
Align the right edge of the material so that it is parallel to the gradations of
the rulers (in two locations: one on the top and one on the bottom).
*: Ruler gradation
Place the left and right pinch rollers over the grit
rollers on both edges of the material.
Position the pinch rollers on the edges so that each one is 25 mm or more
inside of the respective left or right edge of the material.
1: Grit roller
2: Left edge of the material