US Digital

US Digital offers a wide variety of standard rotary encoder disks. They may be ordered as a stand alone disk (see below) or as a codewheel (see the Disks page). These rotary encoder disks are made from mylar polyester film. This material allows for a wide temperature range of -70 °C to +100°C and are virtually unbreakable. There is no minimum order.

Custom disks featuring special resolutions, diameters (up to 12") and index options are available (contact the Sales department). An alternative to designing a custom disk for a special resolution is to use the EDIVIDE encoder resolution divider. The EDIVIDE allows users to customize resolutions to specific applications (see the EDIVIDE page).

DISK-1 has an outer diameter (OD) of 1". The optical radius of the disk is .433". The optical radius is defined as the distance from the center of the disk to the middle of the quadrature track. We recommend that the shaft or hub diameter the disk is designed to fit be .001" to .002" larger than the disk hole diameter (ID). This gives an interference fit that ensures disk concentricity. The drawings shown represent our standard disks.

The maximimum allowed RPM of the disk is typically limited by the maximum output frequency of the encoder module. The maximum allowed RPM is calculated as follows:

Max. RPM = (60 * Fmax) / CPR

Where Fmax = maximum encoder module output frequency and CPR is the Cycles per Revolution of the disk.

The index track option is not available on the following resolutions: 110, 120, 540 and 1016 CPR. The following resolutions are only available with the index option: 32, 720, 900 and 1250 CPR. Other resolutions are available with or without an index track.

Mechanical alignment drawings for optical encoder rotary disks and optical encoder modules are available (see the EM1 and HEDS pages).