Riso V8000 Series, Technical Manual

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[9 - 2]
CHAPTER 9. VERTICAL PRINT POSITION SECTION
Mechanism
1. Vertical Print Position Mechanism
Both the 1st and 2nd print drums are equipped with separate vertical print position mechanisms that are
incorporated into the drum drive units.
The two print drum drive units are identical, but phase with respect to the paper drum differs when
mounted in the machine.
The print drum drive unit incorporates a planetary gear mechanism. The vertical print position is
controlled by the print positioning pulse motor, while the datum position is checked by the vertical
centering sensor.
The initial vertical print position (home position) is the position in which the vertical centering sensor
switches from ON to OFF as the print positioning pulse motor rotates in the direction to bring the image
down.
If the vertical print position key is pressed while the machine is in idle, the panel display changes, but the
motor still does not rotate. The actual print position does not change until the START button is pressed
for the print operation.
If “0” is selected by test mode No. 091, the print position changes only at the start of the printing.
If “1” is selected by test mode No. 091, the print position changes simultaneously during the printing.
The print positions is altered in increments of ±0.1 mm by a press of the print positioning key, and can be
varied continuously by keeping the key depressed.
Vertical print positioning is performed under the following circumstances:
1. When the vertical print positioning key is pressed during printing.
2. During print preparation movement (moves to home position and then to the memorized position).
3. When the machine power is turned ON.
P0912
2nd print drum drive unit
1st print drum drive unit