Estimated Arrival: Between May 20 and May 26. *ETA to USA Only
Shipping & Returns: Satisfaction guaranteed 30 day return policy.
Bob's Knobs offers knobs for all versions of the Celestron 8” f/10 Schmidt Cassegrain secondary with either standard or metric collimation screws, including Fastar, non-Fastar, and the classic orange tube. Select knobs for your telescope from the list below. Please use care to select the correct knobs for your telescope. Each knob set is different and they are not interchangeable. Price is for a complete set of knobs.
- These knobs will fit orange tube C8 models made prior to 1980. The secondary has factory set-style collimation screws with a fourth central screw in the secondary housing.
- Two sets of knobs, each with a different screw length, are included with your order. Use the length that fits your telescope best. There should be two or three screw thread turns above the secondary housing and the dust cover should fit without contacting the knobs.
- Do not adjust the center screw; this is the secondary pivot screw.
- The Celestron 8” SCT uses either standard 6-32 or metric M3 collimation screws. Allen, silver Phillips, and set-style factory collimation screws have standard threads. Most black Phillips screws are metric. See our hints and our Celestron technical paper.for more information. If you order knobs with the wrong screws, contact us using the link at the bottom of this page for return instructions.
Black plastic, 13mm (1/2”) diameter
Black anodized aluminum alloy
We know that once you've placed your order, you are anxious to receive it! We make every effort to get your order shipped out to you as quickly as possible.
As soon as you place your order, you will receive an order confirmation e-mail. This means that we have received your order in our system and pre-authorized your credit card for the purchase. We will process the charges to your credit card and your order will ship within five business days from the date of your order. We will send you tracking information within 24 hours of your order leaving the warehouse to the e-mail address you provided when checking out. If you do not receive tracking information from us within six business days of your order, feel free to follow up with us at email@example.com.
Standard shipping time in the US is between 3-5 business days, though it can vary slightly depending on the destination. We typically For updates on your shipment you can enter your tracking number here.
We distribute nationwide via UPS and Fedex. Unfortunately, at this time we are not able to provide expedited or international shipping.