V20160909
1
Collimation and Secondary Spacing Procedure
The CDK optical design has four optical elements shown in Figure 1. The primary mirror
and the two-element lens group are permanently mounted and aligned at PlaneWave
Instruments. The secondary mirror is movable to allow fine collimation and to set the
spacing between the primary and secondary. To get the best performance out of the CDK
optical system, the optics must be collimated and the primary-to-secondary mirror spacing
must be set. Please note that the primary-to-secondary spacing is set at the factory and
typically does not need to be adjusted unless it was moved after shipping.
Figure 1: The optical layout of the CDK system. The system contains 4 elements: the primary mirror, the
secondary mirror, and a two-element lens group.
Step 1: Collimation / Spacing Adapters for the CDK 14/17/20/24
(For CDK 12.5 proceed to Step 1b below)
If your CDK came with the optional Hedrick focuser (200340) attached, You must first
remove the attached focuser before attaching the Ronchi Adapter and Spacer.
a.
Use an Allen wrench and remove the three socket head bolts that holds the focuser
retaining ring. Make sure that you are holding the body of the focuser while removing
the screws
Focuser
Mounting
Screws
Focuser
Retaining
Ring
Figure 2 – Focuser and Retaining Ring
