Bob's Knobs Celestron Newtonian/Dobsonian Knobs

We offer knobs for the Celestron StarSense Newtonian primary with factory collimation screws only, and for the StarSense Newtonian secondary (all except the LT series). If your StarSense 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. Price is for a complete set of knobs.

Knobs for StarSense Explorer Newtonian Primary with Factory Collimation Screws

Part: SWpri
Fits: StarSense Explorer 8 and 10 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

Notes:

1. Our knobs will fit only a primary with factory collimation screws. If your telescope already has factory collimation knobs our knobs will not fit. Most Explorer 8 telescopes have factory collimation screws and most Explorer 10 telescopes have factory collimation knobs.
2. Black knobs with spacers replace the factory flathead Phillips collimation screws. Red knobs replace the factory set-style (grub) locking screws.
3. 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.
4. Protect the locking knobs from damage, and do not support the OTA using the locking knobs as feet.

Knobs for StarSense LT127 Primary with Factory Collimation Screws

Part: CPS127pri
Fits: Celestron StarSense LT127 telescopes.

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

Notes:

1. Our knobs will fit only a primary with factory collimation screws. If your telescope already has factory collimation knobs our knobs will not fit.
2. The primary collimation and lock screws are the same diameter and differ only slightly in length. The primary collimation adjustment screw is slightly longer than the primary locking screw. We now provide locking screw knobs that are red in color so they can be identified easily.
3. Protect the primary knobs from damage, and do not support the OTA using the knobs as feet.

Knobs for StarSense Newtonian Secondary

Part: CNsec30 or CNsec35
Fits: StarSense DX and Explorer Newtonian telescopes.

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

Notes:

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, some telescopes require knobs with 35 mm screw length.
2. If your secodary looks like the factory photo, our knobs will fit.