Okuma OSP 5000, Электротехническое обслуживание, Учебное пособие

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7-3
Okuma America Corporation
Lathe Lathe
Lathe Lathe
Lathe
Rev. 8-21-01
BACKLASH
The backlash compensates for the lost motion on each axis when the axis feed direction
is reversed. The set backlash value is subtracted from the value read by the absolute
position encoder when the axis motion is reversed. Typically if the backlash setting is
higher than .0015 inches, the ballscrew assembly needs to inspected for mechanical lost
motion problems.
PR ZERO OFFSET
This is the zero offset for the absolute position encoder. This parameter can be used as
the difference in position between the previously and currently mounted encoder. This
parameter is usually set to zero.
STROKE COMP
Stroke compensation makes up for axis positioning error. The tolerance for every 100
mm of travel is 3 µm. If the positioning error is greater, the error is compensated by this
parameter.
The system parameters are factory set and recorded on the OSP control card that is sent out
with every machine. If an encoder has to be changed, then these SEL’s and zero offsets will
have to be reset.
Rapid
This parameter is on the second page of the system parameter menu. It is accessed by
pressing the Page down button on the NC operation panel after accessing the system
parameter menu.
The control calculates RCON every 12.8 msec. The amount of travel it calculates is
determined by this parameter. This Rapid parameter is referred to as the “feed unit
amount”. The feed unit amount is expressed as µm/12.8 msec. Setting this value too
high will generate alarm 101 “CON velocity”.
Accel Rapid
This parameter is referred to as the “acceleration unit amount”. The acceleration/
deceleration time is set by this parameter. When the axis starts moving, initially the feed
unit amount is “0”. The amount calculated is increased by the acceleration unit amount
every 12.8 msec until the feed unit amount (Rapid) is reached. The same happens in
reverse when an axis is commanded to stop. Every 12.8 msec the feed unit amount
(Rapid) is reduced by the acceleration unit amount (Accel Rapid) until RCON reaches
“0”.