Help with collimation 16"dob

[todd8137]

Right am have in a few probs in astro baby's guide in the secondary I did the white and brown paper) i do not see a white circle the whole,of the secondary is white no matter what I do I do not see a circle just all white

Can any one come and help me soon as some one shows me I will be able to do it after I do not mind paying for the services and any fuel costs I am happy how to do the prime mirror just getting the secondary is blowing my brains at the minute I live 8 miles south of Chesterfield

Cheers pat

[Beulah]

I wish I could Pat, I have the same dob as you. Can you take a picture of what you mean?

[Moonshane]

hi Pat

A bit far for me too unfortunately but what are you using to look down onto the secondary?

maybe my guide is a bit easier to understand?

http://stargazerslounge.com/topic/197640-collimation-and-star-hopping/

[todd8137]

It's the 3rd part of astro baby's guide do I centre the primary in the centre of the secondary ,see pic a ( crude I no)

Or on the edge of the secondary pic b, I have drawn the 3 clips on the image pat

[faulksy]

only just getting my head around this as well, but pic b is that the off set ?

[todd8137]

No I want to no where I should See the primary in the secondary's hen use in the 3 bolts not sure if I should have it dead centre or on the edge as in pic b

Pat

[Moonshane]

This should help. it shows the three stages - centre the secondary under the focuser then centre the secondary to the primary then centre the primary to the secondary. you might have to repeat these last couple of steps a few times.

[Moonshane]

it was from here by the way

http://www.skyandtelescope.com/howto/diy/3306876.html

[Dreadz]

Going back to your original post. If you're following astrobaby's guide you wont see a white circle in the secondary, the whole secondary will be white. You're adjusting the secondary to appear as a circle and central to the focus tube (the same amount of coloured paper visible all around it)

What are you using to collimate? Cheshire? Laser?

Sent from my GT-I9300 using Tapatalk

[todd8137]

Going back to your original post. If you're following astrobaby's guide you wont see a white circle in the secondary, the whole secondary will be white. You're adjusting the secondary to appear as a circle and central to the focus tube (the same amount of coloured paper visible all around it)

What are you using to collimate? Cheshire? Laser?

Sent from my GT-I9300 using Tapatalk

As suggested a coli cap from flow and a Cheshire all done now (a think ) just need to Center spot the primary and it's done failing that will start again thanks

Pat

[todd8137]

Thanks that me sorted ,now for putting a donut on the primary but I have done the hard part I hope

Pat