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Collimation help

ChrisR36

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ChrisR36

ChrisR36

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Hi all,

I'm at my wits end with my telescope, and I was wondering if anyone can help, or point me in the right direction.

For the past 5 years (yes, 5 years) I've been trying to collimate my 10 inch Dob. It sits in the corner gathering dust, and every year or so, I make another attempt to line up those mirrors, always in vain, and then back in the corner it goes to gather more dust.

I've gone beyond advice. I've tried following countless guides on the internet, I've tried different methods like the Cheshire Eyepiece, and the Laser Collimator. Truth is, I just can't do it. I've got to the point where I'm seriously considering dumping this scope and getting a 5 inch reflector that I've seen in Argos on my store card (It's all I can afford)

This is my last attempt to put it right really before I give up. I'm wondering if there's anybody in the Exeter/Exmouth area who can collimate my telescope? Obviously, I'm more than happy to pay to get the job done. Failing that, can anyone tell me if there's a place in Devon that offers a collimating service? A shop or a specialist? I wouldn't even know where to start looking to be honest.

I'd be extremely grateful, it used to be a great telescope, and all it is now is a waste of space :)

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faulksy

faulksy

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Hi all,

I'm at my wits end with my telescope, and I was wondering if anyone can help, or point me in the right direction.

For the past 5 years (yes, 5 years) I've been trying to collimate my 10 inch Dob. It sits in the corner gathering dust, and every year or so, I make another attempt to line up those mirrors, always in vain, and then back in the corner it goes to gather more dust.

I've gone beyond advice. I've tried following countless guides on the internet, I've tried different methods like the Cheshire Eyepiece, and the Laser Collimator. Truth is, I just can't do it. I've got to the point where I'm seriously considering dumping this scope and getting a 5 inch reflector that I've seen in Argos on my store card (It's all I can afford)

This is my last attempt to put it right really before I give up. I'm wondering if there's anybody in the Exeter/Exmouth area who can collimate my telescope? Obviously, I'm more than happy to pay to get the job done. Failing that, can anyone tell me if there's a place in Devon that offers a collimating service? A shop or a specialist? I wouldn't even know where to start looking to be honest.

I'd be extremely grateful, it used to be a great telescope, and all it is now is a waste of space :)

cant help you mate but someone should be along soon who can.all i can say is dont give up someone from here will help i am sure of it some real good peeps on here

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John

John

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First Light Optics - see banner at the top of the page, are based in Exeter - give them a ring tomorrow - perhaps they will be able to help.

Have you actually tried looking through the scope in that 5 year period ? - it may not be that far off collimation.

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daz

daz

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Chris

I might be making an offer I can't keep but .....

Am on holiday in Devon at the moment, and just happen to have my collimation tools with me.....

I am in Winkleigh (other side of Crediton) so not a million miles away.

If I can persuade the wife to let me out for a couple of hours, could whip over Saturday AM to take a look. I go back home Sunday morning, so it's really my only chance.....

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John

John

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I was thinking about FLO as well - I was there today of all things - but they may not have time...

Fair point Daz.

Lots of astronomers in that part of the world though - the folks at the Norman Lockyer Observatory (Sidmouth) are not far away and very helpful :)

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ChrisR36

ChrisR36

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Thanks for the replies! brantuk, it's a solid tube Dob, and I have no idea which laser I have, I bought it from eBay about 5 years ago, and it came in a plain white box, and there's no print on the laser itself. I can post a photo of it on here if that's any help?

jahmanson, I looked through the scope the last time I attempted to collimate it. I tried to focus on a bright star, but all I could see was a large grainy blob, with a big black "X" on it, which I assume was a reflection of the spider mount. I will definitely give FLO a call tomorrow, thank you.

And thanks faulksy for your comment, I haven't quite given up yet, I have renewed hope in finding this forum :)

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John

John

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Sounds like the scope was not in focus - the big "X" and the blob is the shadow of the secondary and will dissapear when the scope is in focus. Is the scope branded at all - that would help ?

If you could post a pic of the scope that would help too.

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daz

daz

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That might be easier, if FLO can't help. I am at a friends house, so could not confirm you visiting till Friday.

I am 99.9% certain it would not be an issue, but I will confirm Friday - assuming FLO have not been able to help.

One way or another, we'll get you collimated this week :)

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brantuk

brantuk

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You've got some great ideas and offers there Chris - but if you still need help afterwards let me know and I'll pm you my number. If you call me I can maybe help talk you through it :)

Pics would be useful but from specific angles, and you might need a new/better collimator. Another idea - if you can get to a star party or a local observing group meeting or astro soc someone would be sure to help in person.

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ChrisR36

ChrisR36

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When I last collimated, I put a low mag eyepiece in, and it wouldn't focus on the star. The best image I could get was the grainy blob with the big "X"

Here's a photo, let me know if I need to post more pics from any specific angles. Thanks again everyone for your help!

20110831223916.jpg
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brantuk

brantuk

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Looks like it's been moved Daz - there seem to be two holes just above it. Looks like the original focuser position.

(those are the photo angles I was gonna suggest lol)

Edit: Nope I'm talking rubbish - just realised there's no hole for the drawtube lol. :)

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Moonshane

Moonshane

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I think they are the spider fixings?

one way to try focus is hold the eyepiece to your eye but out of the focuser further and further until it is in focus - do this at night pointing to a clear sky. this will tell you (I hope) that your answer is an extension tube.

as John says collimation just means your image will be less good than it could be not totally blurred. hope you get sorted - unusual scope

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John

John

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I'm old enough to remember a chap called Nigel Wakefield who made and sold dobs like that. He was based in Radstock, Somerset I seem to remember. Stopped selling them long ago though.

I think the 2 holes / screws above the focuser might hold the secondary supports in place. Similar to the old Astro Systems arrangement perhaps ?.

The whole scope looks in good order so it would be good to get it working for Chris :)

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ChrisR36

ChrisR36

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I'm sorry daz, I have no idea what the focal ratio is. As it was built privately for me, I didn't get any specifications with it. The two 'holes' just above the focuser are actually screws which are holding the spider mount in place inside the tube.

Ok, here are some more pics:

dscf1105g.jpg

dscf1106m.jpg

star250.jpg

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