Bob's Knobs are the BEST option for tool-free collimation.

Simple to fit and easy to use.

Collimate your telescope without an Allen key or screwdriver! 

Instructions are supplied but can also be found online as well as useful FAQ.

IMPORTANT: Please ensure the Bob's knobs threads and factory screw threads match before installation. 

Knobs for Celestron C6-N/NGT, C8-N/NGT, and C10-N/NGT Primary

Part: SWpri
Fits: Celestron C6-N/NGT, C8-N/NGT, and C10-N/NGT Newtonian 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

1. The telescope optical tube assembly will clear the Dobsonian rocker box with primary knobs installed.
2. 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.
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 now red in color.
4. Some telescopes have a cover over the primary collimation screws. This cover must be removed and set aside when Bob’s Knobs are installed.
5. Protect the locking knobs from damage, and do not support the OTA using the locking knobs as feet.

Knobs for Celestron C6-N/NGT, C8-N/NGT, and C10-N/NGT Secondary

Part: CNsec30 or CNsec35
Fits: Celestron C6-N/NGT, C8-N/NGT, and C10-N/NGT 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.

Knobs for Sky-Watcher Newtonian Primary with Factory Collimation Screws

Part: SWpri
Fits: SkyWatcher Newtonian telescopes with factory collimation screws. If your scope already has factory fitted collimation and lock knobs then these are a different design and cannot be replaced with this part. 

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 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.

Knobs for Sky-Watcher 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

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, the 12”, 14”, and 16” sometimes require knobs with 35 mm screw length.

There are currently no specifications available for this product.

Bob's Knobs Celestron / Sky-Watcher Newtonian Collimation Knobs Questions & Answers

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