Bobs Knobs for an OO VX10

[Hobbes]

Does anyone know which Bob's Knobs will fit the secondary of my Orion Optics VX10?

[Tinker1947]

Not sure how close to this company you are, there stainless steel and cost about a fiver......

http://a2a4.com/acatalog/KNURLED_THUMB_SCREWS_HIGH_A_2-1.html

[Space Hopper]

I know Rother Valley Optics stock them.

http://www.rothervalleyoptics.co.uk

Give them a call.....they'll have the right ones i'm sure......

[jetstream]

Great info- anyone know the thread size for the screws?

[Hobbes]

Thanks for the advice. I've called Rother Valley Optics and they aren't sure but I'll measure one of the original screws this evening and they will let me know which I need.

I'll post the info here.

[Hobbes]

Well the collimation screws measurements as follows:

Dia: 4mm

Shank length 35mm fully threaded.

Rother Valley Optics do have an equivalent in stock but at £21+postage they seem rather pricey for what are basically a standard thumb screw to me so I'm going to order some of these http://www.wdsltd.co.uk/product/3338/adjusting-screw-steel-metric-wds-605 at half the price and see how I get on. They have exactly the same measurements as Bobs Knobs so I'm hopeful I can save a few quid.

[faulksy]

Well the collimation screws measurements as follows:

Dia: 4mm

Shank length 35mm fully threaded.

Rother Valley Optics do have an equivalent in stock but at £21+postage they seem rather pricey for what are basically a standard thumb screw to me so I'm going to order some of these http://www.wdsltd.co.uk/product/3338/adjusting-screw-steel-metric-wds-605 at half the price and see how I get on. They have exactly the same measurements as Bobs Knobs so I'm hopeful I can save a few quid.

i bought mine from 365 astronomy, dirt cheap there

[Mark at Beaufort]

Well the collimation screws measurements as follows:

Dia: 4mm

Shank length 35mm fully threaded.

Rother Valley Optics do have an equivalent in stock but at £21+postage they seem rather pricey for what are basically a standard thumb screw to me so I'm going to order some of these http://www.wdsltd.co.uk/product/3338/adjusting-screw-steel-metric-wds-605 at half the price and see how I get on. They have exactly the same measurements as Bobs Knobs so I'm hopeful I can save a few quid.

Rob thanks for the info and the link to WDS. I bought an Orion VX8 last year and wanted to change the secondary mirror bolts. I have used WDS in the past for handles for my 10" Dob and the quality was very good. Based on your measurements I ordered 3 bolts which arrived this morning - excellent quality. Installed and re- collimated - very easy.

Thanks again Rob

[Stu]

Just for reference, 365 Astronomy do these too. They also have some useful bits like stiffer spring kits etc

http://www.365astronomy.com/Set-of-M4-Thumbscrews-for-Secondary-Mirror-Collimation-set-of-3-screws.html

[zidder]

I made some myself very easy and cheap to do

Length of 4mm s/s threaded rod cut to 38mm, leaves 35mm thread showing, radio knobs off ebay 3.06 for ten,araldite rod into knob

[Hobbes]

Just for reference, 365 Astronomy do these too. They also have some useful bits like stiffer spring kits etc http://www.365astronomy.com/Set-of-M4-Thumbscrews-for-Secondary-Mirror-Collimation-set-of-3-screws.html

Thanks for the link. Looks like a lot of useful stuff. I'll keep it bookmarked