6-19
DVW-250/250P
8. Upper drum eccentricity adjustment
(1) Slowly turn the upper drum assembly coun-
terclockwise for one turn and check that the
indicated deflection of the gauge meets the
following specification.
Specification: Within 3
µ
m
If the specification is not met, repeat the
following three steps and adjust until the
specification is met.
(a) Slowly turn the upper drum assembly
counterclockwise and check the maxi-
mum and minimum values of the indicat-
ed deflections.
(b) Turn the upper drum assembly until the
minimum deflection value indicates.
(c) Push the upper drum assembly in the
position opposite to the measuring probe
by 180 degrees toward the direction of
the arrow so that the pointer deviation is
1/2 between the maximum and minimum
values.
n
If the indicated deflection did not move when
pressing the upper drum assembly by finger,
loosen the four screws that secure the upper
drum assembly. If the indicated deflection
easily moved when pressing, tighten the
screws a little.
(2) Set the torque screwdriver to 9.8
×
10
–2
N•m
(1 kgf•cm). Put the torque screwdriver in the
four holes on the board of the upper drum
assembly. Tighten the four screws in the
sequence shown in the figure.
n
When tightening the screw just after eccen-
tricity adjustment, be sure to tighten them to
9.8
×
10
–2
N•m (1 kgf•cm).
(3) Set the torque screwdriver to 24.5
×
10
–2
N•m
(2.5 kgf•cm).
(4) Tighten the four screws in the same sequence
as in step (2) using a torque screwdriver.
(5) Re-check that the specification is met.
6-4. Upper Drum Assembly Replacement
Upper drum eccentricity
adjustment tool
Upper drum
Press in this direction
3
2
4
1
