GRAPHTEC FC9000-75 Service Manual page 84

(3) Verify that the Y belt is centered and does not move up and down when the Y-slider is moved from left
to right several times. The Y-slider belt should not move up and down more than 1.5 mm.
Y belt tension
adjustment screws
When the Y belt is moving up, tighten the lower screw a little.
When the Y belt is moving down, tighten the upper screw a little.
FC9000-UM-251-9370
7 DISASSEMBLY AND REASSEMBLY
The Y belt should not
move up and down more
than 1.5 mm.
Y belt
7-46