Quote:
Originally Posted by gjelke
2. The Primary/secondard mirror all seemed to be in good condition ie no cracks or chips etc. What I have noticed is that there is a lot of dust in the tube. I am going to have to take out the primary mirror and follow Mike Salways process on this and give the scope a clean.
3. When I have had attempts at collimation what I have noticed is that the secondary is easy to do but the primary is a challenge. What I did notice is that mirror doesn't move freely when the locking bolts are loosened. So what happened to me is the mirror moved unpridictably and I often had to reset collimation screws and start again.
4. What I have noticed is that the laser collimator gives different results depending on where and how it is placed in to the focuser. The other issue I have learn't is that the laser collimator needs collimation -grr. More learning to do. What I now know is that a laser collimator is just part of the process of aligning the scope.
5. When collimating the scope I noticed that when I move the scope from the vertical to the horizontal the return beam dot moves on the collimator - I don't know why this happens. I suspect that I caused this when I tightened the tension bolts to better hold position when I attach my camera. Loosening them did lessen this effect but it is still there.
Cheers
Greg
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Greg,
2. Is the primary mirror itself really that dirty? Only clean it unless it's really needed.
3. When you unscrew the locking bolts, the mirror isn't meant to move "freely". You need to adjust the larger collimation screws, one out then one in each time, to re-angle it and get the right collimation. The locking bolts will just fix it so that it doesn't bounce around on the collimation bolt springs.
4. Hold the laser collimator firmly in the focuser and turn it. If the laser dot moves in a circular path about the primary mirror centre, it's out of collimation.
5. This is probably because of some slack in the focuser. The laser collimator is quite heavy and will exaggerate the slack.
Regards, Rob