I got a laser and test my refractor. The reflection was in the center even if the spot on the objective was a little bit off. I tried perfecly center the spot on the objective but not so easy to find out where is the issue.
The laser has a play in the 1,25 adapter, the adapter has a play in the drawtube and the rawtube may not well aligned...
Even with compression ring design when i tighten a tumbscrew, it moves the spot.
And the laser itself is needed to be collimated. I tried to rotate, and saw it "circling" a little, but i can only rotate it with loose thumbscrew so when i touched the laser, the spot moved...
At last my method to collimate the laser: I mark the spot position when everything is tight then loose a thumbscrew and rotate the laser 90 degerees, tight and mark again . I adjust the laser until the spot stays on the same mark. I hope that after each "loose and tight" the laser was the same position...