orion focuser

I just received my first scope, a Skyquest 8" Dob. When I try to barely adjust the focuser to attempt a fine focus, the focuser tends to "rock" the field of view one way and then the other way when I reverse the focus. 2 questions: is this normal? and will a different type of focuser eliminate this "rocking" back and forth?

On the top of the focuser, on either side of the locking thumbscrew, you will see a little hole. A 1.5mm allen wrench fits the setscrews in there.

Gently tighten them until you take up the slop in the focuser without making it too tight to turn the focus knobs.

You should see much less image shift after that.

You can also adust tension on the focus knobs my tightening or loosening the four phillips screws on the plate beneath the focuser.

Hope this helps. Let us know how it works out for you.