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DOB Maintenance
This is what I have experienced so far - I hope this is relevent to the thread.
When I go the scope we (seller and I) tested the the collimation and it was close. I am just learning this stuff as our 114mm reflector didn't seem to need it.
1. The scope is in good physical condition so no external maintenance was required. The scope moves well in all directions. What I did notice is that one of the screws that attach the tension mounts has become loose and needs to be tightened - another reason to remove the primary mirror.
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.
This is what I have learned so far - but the biggist thing I am learning is patience - with the weather and everything else including my own skills or lack there of at the moment.
Cheers
Greg
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