Bob's Knobs 3 collimating knobs for Meade Lightbridge/Astro-Tech Newtonian secondary mirrors


Availability: In stock

These no-tool collimation knobs fit the secondary (diagonal) mirror of Meade 8" to 16" LightBridge Dobsonian reflector telescopes and all Astro-Tech Dobsonian and imaging Newtonians.
Our Product #: BKLBSEC
Bob's Knobs Product #: CNsec35

Product Description

These knobs make it easy to collimate the secondary (diagonal) mirror of your Meade 8" through 16" LightBridge Dobsonian reflector, Astro-Tech 6' through 12" imaging Newtonian, or most other brands of 8" through 16"  Dobsonian reflectors for optimum image quality. You don't need any tools, so you never have to worry about dropping the Philips head screwdriver that you need to collimate the factory screws and losing it in the grass in the dark (or, worse yet, dropping it onto the scope's primary mirror).

Separate sets of six knobs (#BKLB10P for the 10" LightBridge, #BKLB12P for the 12") are also available to replace the screws used to collimate the scopes' primary mirrors that need a flat blade screwdriver to adjust. Purchasing both sets of Bob's Knobs (separately or in money-saving packages containing both, #BKLB10ST for the 10" and #BKLB12ST for the 12") eliminates the need to carry two different screwdriver types out into the field. Installation of the knobs is a snap with the included instructions, and you can undo the modification at any time.

The screws used in these Bob's Knobs are made of stainless steel. The knobs on the screws are knurled black plastic, 13mm (1/2") in diameter. The knobs are small enough not to impinge on the scope's light path, yet large enough to grasp and turn easily, even when wearing gloves in cold weather. The factory dust cover will fit normally with the collimation knobs installed.

Bob's Knobs recommends that you remove one collimation screw at a time and replace it with a knob, then repeat the exchange one at a time with the remaining two screws.

Tech Details

Weight 1 oz.
Warranty No Warranty


Review by:
I use these on my 10" Dobsonian. Frankly, it's almost offensive that telescope manufacturers don't include similar knobs in the first place. Sticking a tiny hex tool into the telescope and trying to make fine optical adjustments is a ridiculous gymnastic routine, not to mention that you could drop the tool and potentially permanently damage your primary mirror.

While you don't have to collimate the secondary often and it's not critical like collimating the primary, it's still going to be necessary eventually, and having these knobs is a godsend. I know that making custom hardware in small batches isn't cheap, so I think these are a fair price and nice insurance against mirror damage. (Posted on 12/28/2018)
How do you rate this product? *