Bob's Knobs for Vixen R200SS Primary
Stock count is accurate & shown in real time.
- This item is out of stock.
- Sign up for back-in-stock alerts to be notified when this item becomes available.
- This item is out of stock.
- We have no ETA from the manufacturer at this time.
- Sign up for back-in-stock alerts to be notified when this item becomes available.
Lower 48 States:
Orders over $50 ship free within the Lower 48 using a carrier and service we select based on your items and delivery location. Faster shipping options may be available at checkout.
U.S. Outside the Lower 48 (AK, HI, PR):
Free shipping on orders over $50 applies to many—but not all—items. Add items to your cart and enter your ZIP code to see available shipping options and any costs.
International Orders:
Free shipping does not apply to international orders. You’ll see available shipping options and costs during checkout. Some items can’t be shipped internationally due to size or manufacturer restrictions. Duties, taxes, brokerage fees, and tariffs are not included and are the customer’s responsibility.
Collimate your Catadioptric or Newtonian reflector style telescopes without tools!
It's easy...just grab a Bob's Knob collimation thumbscrew and turn. You can even do it while looking through the eyepiece on most scopes. These thumbscrews are also much easier to use with gloves on. And perhaps most importantly, 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.
Part: R200pri
Fits: Vixen R200SS telescopes, GSO 4.5" f/12 Classical Cassegrain.
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
Notes:
- 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 for easy identification.
- 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 enter a note in the window provided during checkout.
- Protect the locking knobs from damage, and do not support the OTA using the locking knobs as feet.
Other Information
- Country of Manufacture: United States
Collimate your Catadioptric or Newtonian reflector style telescopes without tools!
It's easy...just grab a Bob's Knob collimation thumbscrew and turn. You can even do it while looking through the eyepiece on most scopes. These thumbscrews are also much easier to use with gloves on. And perhaps most importantly, 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.
Part: R200pri
Fits: Vixen R200SS telescopes, GSO 4.5" f/12 Classical Cassegrain.
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
Notes:
- 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 for easy identification.
- 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 enter a note in the window provided during checkout.
- Protect the locking knobs from damage, and do not support the OTA using the locking knobs as feet.
Collimate your Catadioptric or Newtonian reflector style telescopes without tools!
It's easy...just grab a Bob's Knob collimation thumbscrew and turn. You can even do it while looking through the eyepiece on most scopes. These thumbscrews are also much easier to use with gloves on. And perhaps most importantly, 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.
Part: R200pri
Fits: Vixen R200SS telescopes, GSO 4.5" f/12 Classical Cassegrain.
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
Notes:
- 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 for easy identification.
- 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 enter a note in the window provided during checkout.
- Protect the locking knobs from damage, and do not support the OTA using the locking knobs as feet.
Other Information
- Country of Manufacture: United States
| Free Shipping Graphic | Free US Shipping |
|---|---|
| Hide Found a better Shipped Price on Frontend? | No |
Bob's Knobs for Vixen R200SS Primary