Locking nuts on Dobs

[cyborg421]

I was out observing when I was told that the locking nuts did not need to be too tight. I kind of assumed that locking nuts were exactly that, for locking the mirror in position. Reading on SGL I read that some people have removed them completely......

Can anyone enlighten me?

Thanks

Simon

[Doc]

I don't use mine at all. I found when ever I locked the mirror the collimation went out very slightly so I ended up not using them.

[twotter]

Not heard of that before. I suppose if you're collimating every time you use the scope, or maybe even during an observation session, then it might make things quicker

[cyborg421]

Twotter - are you referring to my question or Doc's comments?

I suppose the question is how do they work? Is the mirror secure/ immoveable without them? Because I've got a 10" Flextube Dob I do have to adjust my collimation regularly as it never seem to extend to the exact same position.

Simon

[John]

I always felt the the locking screws / nuts (on the mirror cell I assume we are talking about) were for when the scope was transported. I don't use them in general use at all - tightening them can actually alter the collimation as well.

With a fast 10" truss / strut scope you would generally need to tweak the collimation each time you use it - I do with my solid tube 10" - I consider collimation adjustment as part of the standard scope set up routine.

[Jason D]

I was out observing when I was told that the locking nuts did not need to be too tight. I kind of assumed that locking nuts were exactly that, for locking the mirror in position. Reading on SGL I read that some people have removed them completely......

Can anyone enlighten me?

Thanks

Simon

Many do not tighten them the proper way and end up losing their collimation.

Go ahead and use them. When it is time to tighten them, do it the same way you would with the main collimation knobs. That is, keep checking for collimation as you tighten them.

Jason