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Post by mckinstry on Apr 16, 2009 22:07:40 GMT
Whew, been working hard at collage but the end is finally in sight. Collimated the telescope on Tuesday and was out watching Saturn, nice and high in the sky. I just can't quite make out any cloud belts from my area but I still love focusing in on the planet. I'd love to see the rings at an angle. Can anyone vouch for a set of thingamajig's that allow you to adjust the secondary mirror without the need for a screw? Collimating knobs for a Newtonian telescope, my searches didn't turn up anything. Also I cant believe I haven't made it out to an observing session yet, if you don't count getting lost at Killylane Hopefully I'll make it to one of the next few. Is there much difference in visibility from Summer to Winter? Apart from the longer daylight hours. Tim
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Post by Simon on Apr 16, 2009 22:17:54 GMT
Tim good to hear you've got some time to yourself coming up.
I will have to ask what brand/make your scope is as I once wanted to get collimating knobs for my Newt but because of the type they don't work for me. There are several options out there so I may be able to find you something.
The problem with visibility in the summer is that it never gets dark. By the end of May until mid August it just doesn't get dark enough, at our latitude, to see any faint objects, only a few Messier objects and very bright NGC objects can be seen but with very little detail. Also summer time is the most inactive time for the club but for me I personally like to use the warm summer nights as a good chance to concintrate my observations of beautiful double/binary stars.
Simon
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Post by mckinstry on Apr 16, 2009 22:38:45 GMT
Sorry, It's a 8" Dobsonian, a Skywatcher Skyliner.
darn, can't have the best of both worlds I guess, nice mild nights but poor viewing vs bitter cold and dark skies.
The allen screw or whatever it's called works fine but if I'm letting people use the telescope then the less time collimating the better.
EDIT - Oh I think I remember Irish bloke bought a set for his 10"?
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Post by Simon on Apr 16, 2009 23:08:44 GMT
Yeah, you'll have no trouble getting a set for a Skywatcher. I can look into it for you but sending Brain an PM would probably get you a more faster response and place to buy.
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Post by nemesis on Apr 17, 2009 1:10:34 GMT
Bob's Knobs are what I use, but they're US based, so I don't know if they do a Skyliner set. I swear by them, although Irishbloke had some trouble with them...dunno what but I meant to check that out as they;re great....two mins gets me set up. Check out Bob's website. We're running out of astronical darkness now until August...maybe got a couple of weeks until it won't be worthwhile!
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Post by maccers on Apr 22, 2009 23:11:30 GMT
Bob's Knobs work for me... if you have a Skywatcher Skyliner then just go for the Orion knobs here: HTH James
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Post by irishbloke on Apr 26, 2009 14:20:39 GMT
Yeah I got me some bobs knobs and fitted them. I found the secondary mirror became very jumpy and harder to collimate. So I went back. However I've been reading about a possible reason for this and a modifcation that other people have used and will probably give it a go. The idea is to make a washer from the side of a milk container to put between the screws and the secondary holder. This allows the screws to move easier without scoring the soft holder metal and changing the movement as a result. Here's the link to Stargazer's lounge where I read it: stargazerslounge.com/equipment-discussion/79004-cure-jumpy-secondary-syndrome.htmland the longer discussion in Cloudy nights: tinyurl.com/c6conuThink I'll give it a go and maybe make use of my knobs! Brian
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Post by irishbloke on Apr 26, 2009 22:05:44 GMT
The thread on stargazers lounge is getting very good. Definitely worth a look at and possibly some work on our reflectors. I struggle with this jerky movement when collimating and if this cures it I'll be a happy man.
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Post by irishbloke on May 4, 2009 13:00:36 GMT
My head was mush from assignments and there was an empty milk jug down stairs so I've just put a plastic disc in between the secondary holder and the collimating now knobs. Just cut a circle of the jug. cut a bit out of the middle and an entrance slit to it and sliped it on when I had the collimating screws out. Didn't want to touch the centre screw at this time. It went on fine and I collimated it dead easily.
I did notice pitting from the screws on the back of the holder and this explains the jumpiness I found when collimating previously. This time turning the knobs resulted in smooth movements in the expected direction.
Seriously if you get jumpy movement when collimating try this. 2min job. Cost nothing. Big improvement.
One happy chappy.
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Post by nemesis on May 4, 2009 18:20:23 GMT
Excellent. I knew it should have been easier with Bob's Knobs for you. Easy-peasy from now on!
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