rory Posted January 14, 2013 Share Posted January 14, 2013 from the usa secondary and primary including shipping comes in at about £30 . does that seem about right or am i missing something ,seems quite alot. Link to comment Share on other sites More sharing options...
Tinker1947 Posted January 14, 2013 Share Posted January 14, 2013 There are these people, i have the secondary and the Polar scope kitted out, cost less then a tenner next day delivery........http://www.a2a4.com/acatalog/KNURLED_THUMB_SCREWS_HIGH_A_2-1.html Link to comment Share on other sites More sharing options...
8kids Posted January 14, 2013 Share Posted January 14, 2013 Make your own, rc pinion gears and m4 bolts. Link to comment Share on other sites More sharing options...
rory Posted January 14, 2013 Author Share Posted January 14, 2013 that pretty neat 8kids. tinker what lengths did you purchase for primary and secondary ? Link to comment Share on other sites More sharing options...
L8-Nite Posted January 14, 2013 Share Posted January 14, 2013 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. Link to comment Share on other sites More sharing options...
billhinge Posted January 14, 2013 Share Posted January 14, 2013 I paid $20 inc p&p a year ago last Jan but that was for a SCT (secondary only) Link to comment Share on other sites More sharing options...
Tinker1947 Posted January 14, 2013 Share Posted January 14, 2013 that pretty neat 8kids. tinker what lengths did you purchase for primary and secondary ?My Secondary screws were i think 25mm, not done the Primary as there quite big and easy to turn...... Link to comment Share on other sites More sharing options...
rory Posted January 14, 2013 Author Share Posted January 14, 2013 right ,thanks tinker.i might try the 25mm from the site suggested. Link to comment Share on other sites More sharing options...
x6gas Posted January 14, 2013 Share Posted January 14, 2013 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? Link to comment Share on other sites More sharing options...
rory Posted January 14, 2013 Author Share Posted January 14, 2013 i need to work out some for the primary. but im happy with that price for the secondary screws. Link to comment Share on other sites More sharing options...
Black Knight Posted January 14, 2013 Share Posted January 14, 2013 Got a fair bit of flaming on here too for daring to undermine Mr KnobsReally? I wonder why? I got a set from 365 Astronomy a while ago. They do the job fine. http://www.365astronomy.com/set-of-m4-thumbscrews-for-secondary-mirror-collimation-set-of-3-screws-p-3196.html Link to comment Share on other sites More sharing options...
kirkster501 Posted January 15, 2013 Share Posted January 15, 2013 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 ! Link to comment Share on other sites More sharing options...
rory Posted January 15, 2013 Author Share Posted January 15, 2013 didnt work out at £12 though, was more like £30 for primary and secondary. just weighing up the options to see whats out there Link to comment Share on other sites More sharing options...
kirkster501 Posted January 17, 2013 Share Posted January 17, 2013 didnt work out at £12 though, was more like £30 for primary and secondary. just weighing up the options to see whats out thereThe BK's for my SCT CPC1100 came in at £13.88 including shipping from the US. Link to comment Share on other sites More sharing options...
Astralstroll Posted January 18, 2013 Share Posted January 18, 2013 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. Link to comment Share on other sites More sharing options...
x6gas Posted January 18, 2013 Share Posted January 18, 2013 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. Link to comment Share on other sites More sharing options...
Stargazer33 Posted January 20, 2013 Share Posted January 20, 2013 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:Thanks. Link to comment Share on other sites More sharing options...
x6gas Posted January 20, 2013 Share Posted January 20, 2013 I think you'll need M3 x 12mm. Link to comment Share on other sites More sharing options...
Stargazer33 Posted January 20, 2013 Share Posted January 20, 2013 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. Link to comment Share on other sites More sharing options...
Astrobits Posted January 21, 2013 Share Posted January 21, 2013 "Knurled thumb screw" tops can be bought from Radio Spares ( RS-online ) as well as the cap screws to match.Nigel Link to comment Share on other sites More sharing options...
Stargazer33 Posted January 24, 2013 Share Posted January 24, 2013 Thanks Nigel, I'll have a look at RS for those. I guess the plastic tops will mean that you can't over tighten them and risk damaging the secondary? Link to comment Share on other sites More sharing options...
Astrobits Posted January 24, 2013 Share Posted January 24, 2013 You'll need a vice to get the tops on and they are pretty tight. I don't know what these screws would contact in the secondary mounting so don't think you should rely on them to prevent any damage.nigel Link to comment Share on other sites More sharing options...
Stargazer33 Posted January 24, 2013 Share Posted January 24, 2013 Duly noted! Link to comment Share on other sites More sharing options...
mindburner Posted January 24, 2013 Share Posted January 24, 2013 The bobs knobs I got we're very roughly cut on the ends and I needed to round them off as they just chewed into the back of the secondary. I was a tad disappointed although other folk have had no issues. Link to comment Share on other sites More sharing options...
Peter Drew Posted January 24, 2013 Share Posted January 24, 2013 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. Link to comment Share on other sites More sharing options...
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