Bob's Knobs Collimation Screws for Vixen R200SS Primary - R200pri

Bob's Knobs   ——   SKU: BOB-R200pri
$49.00 CAD
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Product Info

Bob's Knobs Collimation Screws for Vixen R200SS Primary

Collimate your Telescope without special tools when you use Bob's Knobs! It's easy: Just grab a Bob's Knob Collimation Thumbscrew and turn it. You can even do it while looking through the eyepiece on many scopes. You'll never drop that pesky little Allen wrench or screwdriver into the grass again. Installation is a snap with the included instructions, and you can undo the modification at any time if you wish. The factory dust cover will fit normally with Bob's Knobs installed on your secondary.

  • Installation is a snap with the included instructions
  • Modification can be undone at any time
  • Knobs are crafted from black (or red) plastic,  & stainless steel (silver)
  • No tools required to perform a collimation!

Fits:  The Vixen R200SS telescopes.

Primary collimation:

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

Primary Lock:

  • Knobs: Red plastic, 16 mm (5/8”) diameter
  • Threads: Stainless steel


  1. 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. Locking knobs are now RED color for easy identification.
  2. Early versions of the R200SS primary use metric M5 screws for primary adjust instead of the M4 screws that we provide. You can pull a primary adjust screw, which is the Phillips screw, and measure the thread diameter. If you need M5 primary adjust screws with your knobs, please contact Khan Scope Centre.
  3. Protect the locking knobs from damage, and do not support the OTA using the locking knobs as feet.

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