About this product
Model: bk_cswn_pri
Part Number: SWpri
Bob's Knobs are the BEST option for tool-free collimation.
Simple to fit and easy to use.
Collimate your telescope without an Allen key or screwdriver!
Instructions are supplied but can also be found online as well as useful FAQ.
IMPORTANT: Please ensure the Bob's knobs threads and factory screw threads match before installation.
Knobs for StellaLyra Dobsonian Secondary
Part: CNsec35
Fits: StellaLyra (6”, 8”, 10”, 12”, 16”) Dobsonian telescopes.
Knobs: Black plastic, 13 mm (1/2”) diameter
Threads: Stainless steel
Knobs for Celestron C6-N/NGT, C8-N/NGT, and C10-N/NGT Primary
Part: SWpri
Fits: Celestron C6-N/NGT, C8-N/NGT, and C10-N/NGT Newtonian telescopes.
Primary collimation:
Primary Lock:
- Knobs: Red plastic, 16 mm (5/8”) diameter
- Threads: Stainless steel
Notes: - The telescope optical tube assembly will clear the Dobsonian rocker box with primary knobs installed.
- Knobs with shorter screws and spacers replace the factory flathead Phillips collimation screws. Knobs with longer screws replace the factory set-style (grub) locking screws.
- 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, and they are now red in color.
- Some telescopes have a cover over the primary collimation screws. This cover must be removed and set aside when Bob’s Knobs are installed.
- Protect the locking knobs from damage, and do not support the OTA using the locking knobs as feet.
Knobs for Celestron C6-N/NGT, C8-N/NGT, and C10-N/NGT Secondary
Part: CNsec30 or CNsec35
Fits: Celestron C6-N/NGT, C8-N/NGT, and C10-N/NGT Newtonian telescopes.
Knobs: Black plastic, 13 mm (1/2”) diameter
Threads: Stainless steel
Notes:
- Bob offers knobs with screws having either 30 mm or 35 mm length. Order knobs with a screw length sufficient to allow the knobs to clear the secondary housing. Knobs with 30 mm screws are the most common in this configuration.
Knobs for Sky-Watcher Newtonian Primary with Factory Collimation Screws
Part: SWpri
Fits: SkyWatcher Newtonian telescopes with factory collimation screws. If your scope already has factory fitted collimation and lock knobs then these are a different design and cannot be replaced with this part.
Primary collimation
- Knobs: Black plastic, 16 mm (5/8”) diameter
- Threads: Stainless steel
Primary Lock
Notes: - Our knobs will fit only a primary with factory collimation screws. If your telescope already has factory collimation knobs our knobs will not fit.
- The telescope optical tube assembly will clear the Dobsonian rocker box with primary knobs installed.
- Knobs with shorter screws and spacers replace the factory flathead Phillips collimation screws. Knobs with longer screws replace the factory set-style (grub) locking screws.
- 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, and they are red in color.
- Protect the locking knobs from damage, and do not support the OTA using the locking knobs as feet.
Knobs for Sky-Watcher Newtonian Secondary
Part: CNsec30 or CNsec35
Fits: SkyWatcher (5”, 6”, 8”, 10”, 12”, 14”, 16”) Newtonian telescopes.
Knobs: Black plastic, 13 mm (1/2”) diameter
Threads: Stainless steel
Notes:
- Bob offers knobs with screws having either 30 mm or 35 mm length. Order knobs with a screw length sufficient to allow the knobs to clear the secondary housing. Knobs with 30 mm screws are the most common in this configuration. However, the 12”, 14”, and 16” sometimes require knobs with 35 mm screw length.
Customer reviews
| Average Rating (20 Reviews): | |
16 September 2024 | Peter
Simple but effective. These were for a Brand called Saxon in Australia, but the same as Skywatcher as I was advised by FLO. And they worked nicely.
18 August 2023 | Carlos
Good Knobs, fits excellent in my SW Explorer 130 PDS.
Bob's Knobs StellaLyra Newtonian Collimation Knobs 08 May 2023 | Edward
The worlds most expensive three screws! But worth every penny, as they make collimating the Stella Lyra's secondary mirror so much easier than using a screwdriver. In my opinion they are an essential purchase.
04 May 2023 | James
The price alone is justified by how easy it makes something that you have to do all the time. 5 min job to replace the stock ones. Replacing my existing screws turned my secondary (predictably) completely out of collimation so make sure you know how to collimate your telescope fully before replacing them. FLO got it to me next day, answered my email question quickly and packed it like it was a Fabergé egg, very impressed in general! If they pack some screws that well, I think I know where my next purchase is coming from! great experience.
They work well, but pricey for what they are. 13 February 2023 | D
Bought a set for the secondary mirror on a Stella Lyra 8".
Easy to install, Perfect fit, nice size knob to use. Makes collimation much easier. A brilliant upgrade. I would buy them again.
The price though is way above cost. I imagine Bob living in an enormous mansion. But maybe he deserves it for a clever helpful accessory.
26 January 2023 | John
Works really well and collimating my Skywatcher 200p is now much easier, I can't bring myself to vote anymore than 3 stars because of the price, should cost a tenner max. I reckon you could source similar off the shelf at any decent DIY shop.
12 January 2023 | Andrew
Replacing my secondary collimation Allen key screws with Bob's Knobs is one of the best things I've done with my 200 Newtonian. No more fiddling and worrying about dropping a small key. These should be standard fitting on all reflector telescopes. But them!
I've been using Bob's Knobs on my Newtonian scopes for years and I wouldn't be without them! 26 November 2022 | Greg
Bob's Knobs made collimation of my Newtonian scopes so much easier -- and safer! Collimating with small tools, at night, in the cold, makes it too likely I'd drop the tools down the tube and possibly hit the primary mirror. I love these knobs and wouldn't be without them.
Compatible with StellaLyra 12 dob 10 November 2022 | Levent
I do not need a screwdriver anymore. These knobs fit perfectly and make collimation possible without any tools.
Bob's Knobs - Collimation Upgrade 09 September 2022 | Carl
I recently purchased an 8 inch Dobsonian and being my first I decided to do some research to get familiar with this type of telescope. One of the suggested upgrades was to change the collimation screws for the secondary mirror to these and after contacting FLO who by the way replied back quicker than an asteroid flying through space recommended which type to get (there are two lengths).
Instructions were very clear and I was able to collimate the secondary mirror without using a screwdriver once installed just remember to remove one screw at a time.
Are they expensive... For three screws yes but consider this...
If you have to adjust your mirror with a hex key or screwdriver and it slips out of your hand, you'll freeze and time seems to stand still while you watch where it lands.
Fortunately for you in lands on the floor and not on that super reflective mirror inside the end of that tube.
Also prior I used to tilt the tube just below horizontal before adjusting just in case the above happened but having to crouch so low and look down a tube can be a bit uncomfortable plus that's one less tool I need to carry around.
All-in-All I'm pleased with this little additional upgrade, still as with anything you have to be careful when making adjustments but a lot less worrying 
Thanks FLO top notch service.
Read all 20 customer reviews...
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