Pimp my Dob

[Simon E]

I would use a hammer drill, worked for me when i was mounting a rear view mirror in the other half's car

si

[Fay]

I think this is going to call for a soothing drink Mick, don't like to force you though

[Tony G]

Mick,

Speak to Chris, as he had the same problem to overcome.

Tony G

[mickw]

a soothing drink

Speak to Chris

Both admirable suggestions..............................
As I may see Chris on fight night, it leaves this evening free for Fay's suggestion 

[Rocket Pooch]

Just picked up the mirror after re-coatong - Ooh Shiny 

The centre collimating dot has gone though, fortunately this means I will now be in a position to destroy all the  fine work Galvoptics have done 

Ah ha, ok thats easy to cure, I used to pieces of cotton and just taped them at right anges until I thought they crossed ok then I measure it just to check, took 5 mins.

John, your technique is safer, can you explain?

[JohnP]

It was something along lines of get a sheet of paper (probably A3 for your mirror) & draw a circle on it same diameter as mirror. Cut it out & fold in quarters to find centre. Then cut a small hole (slightly larger than one of those sticky paper reinforcers in the middle). Lay paper on mirror & then gently place hole reinforcer sticky side down in midle hole...

Hope that makes sense,

john

[mickw]

Thanks for that chaps, John's way sounds safest for me - it'll keep my fat fingers away from the surface.

Sadly it sounds like a "no beer" job 

[mickw]

Forgot to mention tonight..................
As you know the lightbridge is completely stripped down - possibly a bad move removing secondary from spider though 

After the spotting of the primary and reassembly will come the C word - collimation.
I intend to use the method demonstrated by Chris at Blacklands - eyeball down the tube at 20 paces to adjust the primary, then align the secondary to the primary as it will also be completely out of whack.
I'm thinking that I should at least be able to get something reasonable as a starting point for proper alignment later.

Am I going about it the right way ?

[Mike]

I thought you had a laser collimator? Using that is far and above the easiest way to collimate it. Collimate the secondary first, then the primary.

[mickw]

I thought you had a laser collimator

I have, I was just thinking of getting things eyeballed first as everything is/will be really messed up 

So, laser it is then 

Cheers

[Ian]

you will of course put the fricking laser on your head, won't you...

[Rocket Pooch]

I thought you had a laser collimator? Using that is far and above the easiest way to collimate it. Collimate the secondary first, then the primary.

Hi,

Because its a parabolic mirror (like a bowel) you can use a laser align it and still have the mirror out, the think I showed Mick was just to ensure the primary was set first.

Then use the laser.

Chris

[mickw]

Yep, that's what I meant 

[Ian]

Mick, have you got access to a cheshire? Once you've got your head around what you're looking at (and that's not hard, start from the outside and work in, they work a treat.

This is one of the best explanations I've seen on using one, including a discussion regarding what doesn't get centred (hint, the secondary reflection *shouldn't* be centred).

[Fay]

Think it may call for a drink when you have read the article, Mick, it made me head for the bottle!!