Crayford 10:1 collimination.
I've been having trouble getting good focus with my 450D and while checking things out have realised that adjusting the tension or lock screws on the crayford focuser moves collimination as both of them will move the focusing tube to some degree. I normally focus on a nearby star before imaging and then lock the focuser with the lock screw so this may be my problem.
What I've done is to tension it pretty tight, I had to also re-adjust the 10:1 set bolt to get 10:1 working after this, and I released the lock screw completely. I then dapped a little lock tight on both screws so I don't accidentally move them again. I have then re colliminated the scope and I'm waiting for the stinking clouds to clear to double check.
How are others dealing with sloppy tubes in these cheap crayfords?
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