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bobs knobs.


rory

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Being an amateur machinist for longer than I can remember, I would say £30, or about $45 is an "unbelieveable" amount of money for something which is nothing more than a socket head capscrew with a pressed on plastic cap, which you can do for yourself in a simple vise; but then again, you pay for what you don't know.

Edit: Screws and caps are available through the McMaster Carr Catalog.

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Got mine from a2a4 too... Got a fair bit of flaming on here too for daring to undermine Mr Knobs too but I agree with the above - a couple of quid and next day delivery when I ordered... What's not to like?

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The way I view it, if you have a scope worth many hundreds, if not thousands of pounds, £12 or so to get the real deal is not much to pay in the great scheme of things. Bob makes his living out of such a mindset. Naturally, if you know where to get the exact bolts for a quid or two then good for you !

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I guess its a personal choice. With my Lightbridge, Meade have gone with half decent knobs on the Primary, but not on the secondary. The secondary doesnt bother me as I can can align it in a few secinds with a screwdriver on a piece of cord. Their springs are still very weak though. So for £10 or so I got a set of Bobs Knobs springs. Yes, Im sure i could have looked around and found some cheaper. But having tried to source other such items and spent a long time trying, I think its an OK investment. I guess the real question to ask is why Meade dont upgrade the springs themselves. Then I guess you could also ask why they dont make a better mount, but a setting circle on it as well as the other mods that us Dob owners are apt to do.

Dave.

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I guess the real question to ask is why Meade dont upgrade the springs themselves.

Dave.

Absolutely. As I have said elsewhere, the collimation screws on my HD11 were crossheads that I think were made of cheese painted black. Even with a high-quality, correctly sized screwdriver they immediately started to burr up. Now I realise that manufacturers save money where they can and that these things are made to a price, but the OEM screws were in no way fit for purpose.

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Does anyone know what M size and length the screws are on the secondary for a Celestron C8 SGT (XLT) with Fastar fitting?

I know that the thumb screws would have to either be longer than the originals, or have a reasonable depth of shoulder on them to allow for the recess in the front of the secondary holder. But if I know the size and length of the originals then I can work out what extra length I need to allow for the recess.

I bought the scope last year from a chap who had bought it from FLO earlier in the same year, so it should be of the latest release.

My secondary holder is the same as this:

post-21511-0-55516600-1358702414_thumb.j

Thanks.

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Thanks x6gas!

I think I have messed up my collimation now any way, as I removed my secondary/Fastar unit earlier tonight in order to clean the secondary of large dust/swarf particles, not realizing that I would have to remove my corrector plate in order to screw it back in!

So I might as well unscrew one of the collimation screws and just measure it.

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Worth placing an aluminum washer between the screws and the diagonal holder. The screws then tend to bite into the washer and do not try and rotate the diagonal whilst finally tightening. If not too tight, you can manually adjust the secondary to square it to the drawtube without disturbing the adjusting screws. :smiley:

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