Brands - JMI



Secondary Knobs for Orion and Sky-Watcher Dobsonians 30 mm


SKU: CNsec30
Manufacturer: Bob's Knobs
Availability: IN STOCK


These knobs with 30 mm screws replace the set factory secondary mirror collimation screws on Orion and Sky-Watcher Dobsonian telescopes. 

Knobs for Orion and Sky-Watcher Newtonian Secondary (30 mm)

Part: CNsec30

Fits: SkyWatcher (5”, 6”, 8”, 10”, 12”, 16”) Newtonian telescopes. Orion SkyQuest XT-series with factory set-style secondary collimation screws. This is the most common XT-series secondary. Suggested for 6-10" models, but see notes below.

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” and 16” sometimes require knobs with 35 mm screw length.

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