Sharp SH-920 Instruction Manual page 18

Leveling:
4.
Machines should be carefully leveled by a 0.02/m precision spirit level and
equally load on the jack bolts. The adjusting procedure is as followings:
4.1 Put a spirit level in the middle of the table (or on its magnetic chuck if any) in
longitudinal and transverse direction, adjust jack bolts until the level bulb
indicates within 0.02/m.
4.2 To obtain good accuracy, it is recommended that the machine should be
leveled repeatedly.
4.2.1 The machine should stand still for 24 hours after final installation and it
is better to ensure that the machine temperature is similar to that of the
ambient circumstances.
4.2.2 Start the machine with hydraulic system to let the table running
reciprocally for at least 2 hours, to ensure the machine gets used to the
temperature of its normal operation condition.
4.2.3 Re-check and adjust the leveling condition of the machine, then regrind
the table (or chuck) surface to make it flat.
4.2.4 Every time the machine level is checked, make sure the table (or
chuck) surface should be reground for accuracy.
4.2.5 The machine will lose its level usually due to machine vibration and
other causes, so it is highly recommended that the machine needs to
check leveling periodically.
4.2.6 Although the leveling operation is troublesome, it is essential for getting
good operation results. It is better to have the machine leveled at
least once every month.
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