Aligning The Disc; Optical Alignment - Renishaw ATOM Installation Manual

Aligning the disc

There are two possible ways to accurately align the disc to minimise eccentricity:
• Optical alignment using a microscope
• Electrical alignment using two readheads
The method chosen to align the disc on the system depends upon the application and available space, etc. It should be noted that the graduations and alignment band are accurately concentric with each
other but not with the glass disc. The following sections outline how to align the disc using these methods.
NOTE: The disc should not be mounted on the black mask on the reverse of the disc (apart from 17 mm disc).

Optical alignment

This method uses a microscope, which could be connected to a camera, to monitor the movement of the alignment band as the disc is rotated.
1. Position the microscope / camera over the alignment band on the disc so that any displacement of the alignment band due to rotation of the disc / hub assembly can be observed.
Alignment
band
Microscope
and camera
RCDM disc / hub
assembly
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