collimation RC10 headaches (again)

[graham.hobart (Graham stevens)]

Hello folks, recently I thought I had collimated my RC 10. But when I put the heavy camera back on it I noticed the weight of the camera moved the primary mirror- one of the primary screws was loose.
So I tightened it up then redid it and it was woeful.
So then I messed about with the primary and now both mirrors are way way off.
SO I need to get the primary back to a certain neutral or base line position then start from scratch again. How can I do this?.
I believe the big silver screws are movement screws and the little dark allen bolts are the lock screws (on the primary) is this correct?.
I put Bobs knobs on the secondary now and it is easier to move but the movements are quite big.
Help!!
Graham

[casstony]

This may help: https://www.astronomics.com/document...on%20sheet.pdf

[pluto (Hugh)]

I have an RC8 but I believe the bolts are the same. From what I've read I think the larger silver ones are push screws and the smaller black ones are pull screws.
In my experience, in practise the load is on the pull screw/s in the direction of gravity and on the push screw/s above so the unloaded screws act as lock screws.

I got Bobs knobs for mine but I find I can't be as precise as with an allen key, especially when my hands are cold, so I've removed them and added a wrist strap (rubber band) to my allen key so I don't drop it on the mirror.

[Paul Haese]

I take it you are using a takahashi collimation scope? If not you need one.

The little screws are the locking screws and the large screws are the collimation screws. Get collimation right first on the rear with the tak scope. The lock them off. The do the secondary collimation with the tak scope to get it ok and then do a star test to get it right.

[graham.hobart (Graham stevens)]

Thanks all for the answers.
But my messing made my mirror way off so here was my cure...
1/ Video camera facing scope (primary mirror) -luckily was a 60Da so could turn the video screen 180" to face me whilst I messed about. -Literally was so far out of kilter I had to use this method to even align basically...then
2/ Cheshire eye piece to align secondary- roughly but bloody hell it works.
3/ Tak scope to finish the job- I was not far off with the Cheshire.
I have to say it is really hard to do this alone. I did it but you would be better off getting some one to help you. And Quicker.
Star test can wait- till the snow stops me thinks!!

[omegacrux (David)]

Glad you got it sorted Graham


David