Can anyone in or around Southampton help with collimation?

[Adam1234]

Hi all, I'm really struggling with collimating my scope, and it's making me really frustrated.

I've read every set of instructions and YouTube videos going and just can't seem to get it right. Every time I think I've got it in collimation, I take a closer look and realise it's not. 

Is there anyone in or around the Southampton area that would be willing to physically show me how to get it in collimation?

Thanks 

[michael8554]

I think you'll need to specify which scope you have!

Michael 

[Ruud]

Adan, in case you use a laser collimator, have you checked if it itself is collimated?

see here:

 

 

[cletrac1922]

Adam

Welcome from Land Down Under

Number of steps first need to establish

As Michael stated, what type of scope you have, and you use away from home

If is is a Dob, how long have you had it, and what makes you think has a collimination issue

I am out 2 or 3 times per month with my club doing presentations with my club primary schools, scout groups, and very rarely need to colliminate my 10" flex Dob

I have become the go to person in my club for colliminiating Dobs

Rock up to your local club, and members there will only be too happy to assist u

John

 

[Adam1234]

4 hours ago, cletrac1922 said:

Adam

Welcome from Land Down Under

Number of steps first need to establish

As Michael stated, what type of scope you have, and you use away from home

If is is a Dob, how long have you had it, and what makes you think has a collimination issue

I am out 2 or 3 times per month with my club doing presentations with my club primary schools, scout groups, and very rarely need to colliminate my 10" flex Dob

I have become the go to person in my club for colliminiating Dobs

Rock up to your local club, and members there will only be too happy to assist u

John

 

I've got the Meade 6 inch Newtonian 

I bought it 2nd hand over Christmas and I thought it was about time to check the collimation with my Cheshire collimating eyepiece (this one https://www.firstlightoptics.com/other-collimation-tools/premium-cheshire-collimating-eyepiece.html) and it did appear to be out of collimation, but I've just made it a hell of a lot worse by trying to correct it. 

It's the secondary mirror I'm mostly having issues with. The primary seems easy to adjust, but I wasn't convinced that the secondary was 100% right so I tried doing some adjustments and I've made it worse and just can't seem to get it right.

I do have a laser collimator but need to check the collimation of the laser so have mostly been trying to use the cheshire. 

Another thing that is frustrating though is I'll put the cheshire in the eyepiece holder, tighten the screws, but then I can move the cheshire around by wobbling it even though the screws are tight and it makes me wonder how do I know if the Cheshire itself is central to the focusing tube.

 

[Jiggy 67]

Have you checked that the secondary is collimated with the focuser?? In other words is the secondary mirror aligned centrally with the focusing tube. If it isn’t, you won’t be able to collimate everything else accurately. For this, it’s best to use a collimating cap

[Adam1234]

10 minutes ago, Jiggy 67 said:

Have you checked that the secondary is collimated with the focuser?

That's one of the things I'm struggling with. 

I don't have a collimation cap. What's the difference between the collimation cap and cheshire (aside from the cheshire being a long tube with crosshairs).

 

[JOC]

Have you followed this guide yet - http://www.astro-baby.com/astrobaby/help/collimation-guide-newtonian-reflector/

I tried all the various videos and other instructions, but get a Cheshire collimator and do everything Astrobaby says and in the order instructed and you will succeed - even I managed it.

[Jiggy 67]

2 hours ago, Adam1234 said:

That's one of the things I'm struggling with. 

I don't have a collimation cap. What's the difference between the collimation cap and cheshire (aside from the cheshire being a long tube with crosshairs).

 

The cap is easier because it enables you to see the walls of the focuser tube, the Cheshire doesn’t. The cap centers your eye in the focuser which is what you need to centre the secondary 

Edited February 11, 2020 by Jiggy 67

[Adam1234]

7 hours ago, Jiggy 67 said:

The cap is easier because it enables you to see the walls of the focuser tube, the Cheshire doesn’t. The cap centers your eye in the focuser which is what you need to centre the secondary 

I've now got a cap on order so hopefully arrives soon.

In the meantime I made a makeshift cap using a bit of paper with a hole in and taped it over the eyepiece holder.

Not perfect, but as you said I was able to see the walls of the focuser, and I could also see the primary mirror clips which I couldn't with the cheshire. 

How are these efforts? 

View with makeshift collimation cap (you can even see the sheep on the kitchen blind 🤣):

 

View with cheshire:

[Jiggy 67]

To centre the secondary, block out the primary with a sheet of paper, otherwise it gets confusing. The secondary should then form a perfect circle in the centre of the focuser 

[Adam1234]

31 minutes ago, Jiggy 67 said:

To centre the secondary, block out the primary with a sheet of paper, otherwise it gets confusing. The secondary should then form a perfect circle in the centre of the focuser 

Yeah I did that, and placed another bit of paper behind the secondary. It seemed to look as if the secondary was centred under the focuser, but I'll double check this evening.