We offer knobs for the SkyWatcher Newtonian primary with factory collimation screws only, and for the SkyWatcher Newtonian secondary (all types). If your SkyWatcher primary is already equipped with factory knobs, our primary knobs will not fit. Select the type of knobs for your telescope from the list below.

A. Knobs for SkyWatcher Newtonian Primary with Factory Collimation Screws

Part: SWpri
Fits: SkyWatcher Newtonian telescopes with factory collimation screws.

Primary collimation
  • Knobs: Black plastic, 16 mm (5/8”) diameter
  • Threads: Stainless steel
Primary Lock
  • Knobs: Red plastic, 16 mm (5/8”) diameter
  • Threads: Stainless steel
  1. Our knobs will fit only a primary with factory collimation screws. If your telescope already has factory collimation knobs (see Item B below) our knobs will not fit.
  2. The telescope optical tube assembly will clear the Dobsonian rocker box with primary knobs installed.
  3. Knobs with shorter screws and spacers replace the factory flathead Phillips collimation screws. Knobs with longer screws replace the factory set-style (grub) locking screws.
  4. Since the factory collimation and locking screws are close together, knobs must be staggered in height. The locking knobs protrude further than the collimation knobs, and they are red in color.
  5. Protect the locking knobs from damage, and do not support the OTA using the locking knobs as feet.



B. Knobs for SkyWatcher Newtonian Primary with Factory Collimation Knobs

Some SkyWatcher models are equipped with factory collimation and lock knobs. Although the lock knob is small, its proximity to the collimation knob prevents replacing it with a larger knob. Furthermore, the primary adjustment knob is of a different design than our replacement knobs.

C. Knobs for SkyWatcher Newtonian Secondary

Part: CNsec30 or CNsec35
Fits: SkyWatcher (5”, 6”, 8”, 10”, 12”, 14”, 16”) Newtonian telescopes.

Knobs: Black plastic, 13 mm (1/2”) diameter
Threads: Stainless steel

  1. We offer knobs with screws having either 30 mm or 35 mm length. Order knobs with a screw length sufficient to allow the knobs to clear the secondary housing. Knobs with 30 mm screws are the most common in this configuration. However, the 12”, 14”, and 16” sometimes require knobs with 35 mm screw length.


Screw length