412LXR Series Product Manual
Chapter 4 - Performance
32
Thermal Effects on Repeatability
Repeatability will not be effected as long as the temperature remains constant. However the repeatability
will be effected as the temperature changes from one level to another. This is most commonly
experienced when starting an application cold. Then as the application runs the 412LXR comes to its
operational temperature. The positions defined when the unit was “cold” will now be offset by the thermal
expansion of the unit. To compensate for this offset, all positions should be defined after the system has
been exercised and brought to operational temperature.
Causes of Temperature Increases
One or more of the following conditions may effect the temperature of the 412LXR base:
•
Ambient Temperature
This is the air temperature that surrounds the 412LXR.
•
Application or Environment Sources
These are mounting surfaces or other items which produce a thermal change that effect the temperature
of the 412LXR base (i.e. Machine base with motors or other heat generating devices that heat the
mounting surface and thus thermally effect the 412LXR base).
•
Motor heating from 412LXR
Since the 412LXR uses a servo motor as its drive, it produces no heat unless there is motion, or a force
being generated. In low duty cycle applications heat generation is low, however as duty cycles increase,
temperature of the 412LXR will increase, causing thermal expansion of the base. With very high duty
cycles these temperatures can reach temperatures as high as 30
°
C above ambient.
Temperature Effect on Accuracy
0
0.5
1
1.5
2
2.5
0
1
5
0
3
0
0
4
5
0
6
0
0
7
5
0
9
0
0
1
0
5
0
1
2
0
0
1
3
5
0
1
5
0
0
1
6
5
0
1
8
0
0
1
9
5
0
2
1
0
0
2
2
5
0
2
4
0
0
2
5
5
0
2
7
0
0
2
8
5
0
3
0
0
0
Travel (mm)
E
rr
o
r
(m
m
)
5 degrees C
10 degrees C
15 degrees C
20 degrees C
25 degrees C
30 degrees C
