3502
Optical Chopper System
17
Figure 10:
Dimensions of Model 3502 Optical Chopper Head. Dimensions in inches (mm).
3.2.2
Chopper Motor
The operating life of the Chopper motor is limited. Long-term use of the motor at
high speed will result in faster wear and a shorter lifetime. Contact Newport for
details about the replacement part, 3502-MOTOR, if this becomes necessary.
3.2.3
Mounting a Wheel
Six wheels are shipped with Model 3502 Optical Chopper, shown in Figure 11
below (these wheels are not included in the Model 3502-BASE, and must be
ordered separately). To install or change a wheel first power off the Chopper
Controller. Secure the chopping head to a work surface. Remove the four 4-40
screws that secure the retaining cap over the wheel, while taking care not to bend
the wheel on the optical pickup. Install the replacement wheel, retaining cap, and
4-40 screws. Do not over-tighten the screws. Please note that if a wheel is bent
during the installation/removal process, it can be very difficult to straighten again.
This may degrade the stability of operation of the Model 3502 Optical Chopper
system, and a replacement wheel may be required.