Maintenance
MPS50SL Hardware Manual
4.2.1. Bearing Centering Procedure
The MPS50SL bearing cage assembly may creep in one direction over time. This is normal, but may require
correction if the cage creeps far enough to risk contact with the corners of the stage base. Scribed lines are
provided on the stage base as a visual indicator of bearing cage centering.
below shows an off-
centered bearing cage on an MPS50SL-050 stage.
Figure 4-1:
MPS50SL-050 Bearing Cage Creep
To correct this problem, the cage can be pushed back into position using a bearing centering fixture, which is
available for purchase from Aerotech. Two fixtures are available depending on travel length, the part
numbers are BCF-MPS50SL-025 and BCF-MPS50SL-050. A drawing of each fixture is shown below for
customers with the ability to manufacture it themselves. The fixture must be soft enough to prevent damage
to the steel balls and rails. 6061 aluminum is the recommended material. The step cut in the fixture captures
the balls to prevent the cage from buckling as it is pushed from the end.
40
Chapter 4
www.aerotech.com
