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Bobs Knobs

abberation

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rory

rory

Posted
Posted

All you really need are some knurled thumb screws which you can buy from the UK at a fraction of the cost.

See my post in this thread: http://stargazerslou...6724-bobs-knobs

And just do a web search for "DIN 464" which is the standard spec for this type of knurled thumb screw.

thanks for the link . might give them a go myself. need o work out particular sizes for 8" skyliner primary and secondary mind ?

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Spec-Chum

Spec-Chum

Posted
Posted

thanks for the link . might give them a go myself. need o work out particular sizes for 8" skyliner primary and secondary mind ?

M4 35mm for secondary but not sure about the primary. I went Bob's knobs for my primary, not bad value for 6 really, but I don't think I will for secondary, only need 3...

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Damo636

Damo636

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For what its worth the Bobs Knobs upgraded springs (same as the ones for 12" Lightbridge) work well on a 200p also and leave collimating the primary much easier. I never got on with the rubber o rings and the springs were so effective I removed the locking screws altogether! As already mentioned, these are an essential upgrade on any 12" GSO manufactured scope. The standard parts are shockingly light and not up to the job.

I found these (8168-227 X3) perfect for the secondary mirror adjustment on both my 8" and 12" scopes....http://www.wdsltd.co.uk/products/Machine-Parts/Plastic-Hand-Knobs/WDS-8168-Thumb-Screw-240/ for around £6 all in.

post-11833-0-12108100-1342558706_thumb.j

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scogyrd

scogyrd

Posted
Posted

<p>

I'll let you know how they fit but they extra 10mm should be spot on imo.

Having bought them I think 30mm might be the best size. 25mm is too short imo, the secondary holder(?) is 20mm and there is a couple of mm gap between that and the mirror so that doesn't leave much scope for adjustment (if you'll pardon the pun). My 25mm thumb screws only just touched the mirror.

And 35 is a bit long imo. They work fine but they just look a bit long... if I'm ever feeling a bit flush I might change them for some 30mm screws.

2012-07-19164857.jpg

Sorry about the large picture. I tried changing the size in photobucket but it wouldn't work.

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Zakalwe

Zakalwe

Posted
Posted

I have just received some of Bob's Knobs for my Celestron C11 (the one with the "Triffid" fastar secondary. Out of interest, I also ordered some of the DIN stainless thumscrews. The Bobs Knobs are longer, and stand clear of the rotating cover. In contrast the thumbscrews are more difficult to get in and you cannot get a proper grip on them.

Errr I don't doubt it, but you can get them three times quicker and at least three times more cheaply also with excellent service direct from a UK supplier.

As I say, you pays yer money...

The BK arrived one day earlier than the thumbscrews in my case!!!

As for cost, the BK cost £13.91. The thumbscrews with post and packaging cost £10.68. They are certainly not three times cheaper. They are (certainly for a Celestron C11) 23% cheaper and dont work as well.

Here's some images showing the difference (click to enlarge)

th_IMG_20120719_180942.jpg

th_IMG_20120719_180955.jpg

The thumbscrews might be OK on a non-Fastar secondary.

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abberation

abberation

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For what its worth the Bobs Knobs upgraded springs (same as the ones for 12" Lightbridge) work well on a 200p also and leave collimating the primary much easier. I never got on with the rubber o rings and the springs were so effective I removed the locking screws altogether! As already mentioned, these are an essential upgrade on any 12" GSO manufactured scope. The standard parts are shockingly light and not up to the job.

post-11833-0-12108100-1342558706_thumb.j

Thats interesting - I didn't realise Bob did upgraded springs - shall have to contact him.

I've taken in all the replies and initially thought I'd go for a UK supplier but the more I read the less confident I was about it as I have had a couple of recent bad experiences in getting some erroneous parts, so I ordered through Bob. Hopefully they will turn up tomorrow. However I think I will get some uprated springs and tackle it all at once.

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rory

rory

Posted
Posted

i dont know what i was doing on the bobs knobs site, but for a set of primary and set of secondary it was $47.00.

im going to source through uk with the links given .

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Spec-Chum

Spec-Chum

Posted
Posted

That's about 30 quid which isn't too bad for 9 bolts (6 primary and 3 secondary) mate. So £3.33 each. Decent bolts for the secondary (30mm M4) are around £3 each from a UK supplier alone.

Don't forget it's in dollars like I did lol

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x6gas

x6gas

Posted
Posted

I have just received some of Bob's Knobs for my Celestron C11 (the one with the "Triffid" fastar secondary. Out of interest, I also ordered some of the DIN stainless thumscrews. The Bobs Knobs are longer, and stand clear of the rotating cover. In contrast the thumbscrews are more difficult to get in and you cannot get a proper grip on them.

The BK arrived one day earlier than the thumbscrews in my case!!!

As for cost, the BK cost £13.91. The thumbscrews with post and packaging cost £10.68. They are certainly not three times cheaper. They are (certainly for a Celestron C11) 23% cheaper and dont work as well.

Well fair enough. I really don't have an axe to grind here, I can only say what I did and report my experience.

When I ordered mine from A2A4 shipping was free for orders over a fiver - I see they now charge which does make a difference but as I said in the original thread, I hadn't spent much time searching for the cheapest supplier.

I'm happy what I did and for me it DID cost three times less at the time and with next day delivery... so please don't shoot the messenger.

Please also note that I was just responding to the OP "can anyone tell me if there is a UK supplier for Bobs Knobs (or similar)."

:embarassed:

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JamesF

JamesF

Posted
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And 35 is a bit long imo. They work fine but they just look a bit long... if I'm ever feeling a bit flush I might change them for some 30mm screws.

Could you not just, like, saw 5mm off the end?

James

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scogyrd

scogyrd

Posted
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Could you not just, like, saw 5mm off the end?

James

I'm sure I could but I'd sooner buy a new set with rounded edges than mess about sawing them.

I'm happy with them as they are though and I can't see me replacing them any time soon.

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  • 2 years later...
michaeldurban

michaeldurban

Posted
Posted

I agree with all of you..

Since I live in South Africa our trip to the local hardware store normally yields

paint, sandpaper and bolts..no specialty items per se..

I did however contacted a spring manufacturer who had new stiffer primary

collimation springs made for my 10" SW flex.

total cost for 6 springs was R 140... or roughly GBP 8,-

not sure what it would cost on your side of the world...but it took me 1 day to source them.

Then again, I like driving around and finding stuff...

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kerrylewis

kerrylewis

Posted
Posted

I bought some Bob's knobs for my primary and they're no different to any other thumbscrews. We're just being ripped off when we buy them.

Everyone can decide whether they are being ripped off or not - I was merely pointing out there is now a UK supplier

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