SCT Collimation without Tools: BOB'S KNOBS
It's easy . . . just grab a Bob's Knob and turn. You can even do it while looking through the eyepiece on most scopes. And you'll never drop that pesky little Allen wrench or screwdriver on your corrector plate, or in the grass again. Installation is a snap with included instructions, and you can undo the modification at any time.
In particular, this model:
Fits: All Celestron 11 inch (28 cm) f/10 SCT versions (metal or carbon fiber tube) with flat secondary housing and standard 6-32 collimation screw threads (not for CPC 1100).
Knobs: Black plastic, 16 mm (5/8 inch) diameter.
Threads: Black anodized aluminum alloy.
Note 1: Make sure the knob threads match the factory screw threads before installing the knobs.
Note 2: The factory dust cover will fit normally with Bob's Knobs installed.
Note 3: Most Celestron 11 inch (28 cm) SCTs made prior to 2006 have the flat secondary housing with standard 6-32 collimation screw threads. If your SCT has the Faster option, order knobs for the "Trifid" Fastar secondary housing instead. Do not use knobs for the Trifid Faster secondary on the flat secondary. The screws on these knobs are too long.
Note 4: The CPC 1100 SCT requires knobs with metric threads. The CPC 1100 secondary can be identified by a factory-installed plastic cap over the collimation screws. Do not use these knobs on the CPC 1100.
Installation instructions are available in English, Spanish, German, Italian and French.