Attach a CDK20 to an AP Female Adapter

Quick answer

To attach a CDK20 to an AP female adapter, remove the focuser, screw the adapter into the rear cell, and secure it with the included locking ring.

Step-by-step attachment process

1. Remove the focuser: Unfasten the screws securing the focuser to the CDK20's rear cell. Gently pull the focuser straight out. Keep the screws in a safe place. Common mistake: forcing the focuser out sideways can damage threads. Pull straight.
2. Clean the rear cell threads: Wipe the exposed threads on the telescope's rear cell with a lint-free cloth to remove dust or debris. Inspect for any burrs or damage. Checkpoint: even a small particle can prevent the adapter from seating flush.
3. Thread the AP female adapter onto the rear cell: Align the adapter's male threads with the rear cell threads. Turn it clockwise by hand until it is snug. Do not use tools—hand-tighten only to avoid cross-threading. Common mistake: over-tightening or using a wrench can strip threads. Hand-tight is sufficient.
4. Secure with the locking ring (if provided): Many AP female adapters include a locking ring that threads onto the adapter after installation. Tighten it against the rear cell to prevent rotation during use. Checkpoint: if your adapter lacks a locking ring, verify it remains firm after attaching accessories.
5. Attach your AP-threaded accessory: Screw your camera, reducer, or filter wheel onto the adapter's female threads. Hand-tighten until snug. Confirm the accessory is parallel to the telescope's optical axis. Common mistake: a tilted accessory can cause vignetting or poor focus across the field.

Product details

• Adapter, CDK20 To AP Female: This adapter mounts in place of a focuser on CDK14/17/20 & 24 models and has standard AP female threads. It allows you to attach AP-threaded accessories directly to the telescope's rear cell, eliminating the need for additional adapters and reducing potential flexure.