peter_4059
21-10-2007, 11:28 AM
Last night I was out for a bit of moon observing. While changing eyepieces I had a look through the empty focuser and noticed three streaks (each about the width of a 7yo's finger) right across the secondary mirror. :scared::scared::scared: I'm not sure how long they have been there and they weren't impacting the moon image noticably but they had to go.
So I've been off to the shop this morning for a bottle of distilled water and cotton wool balls. I can now say I've tried out Starkler's GSO optics adjustment procedure and Iceman's mirror cleaning procedure - thanks to both of you.
I've got to admit that as I removed the secondary mirror I wasn't sure if I was ever going to get it back into the right position given the number of axis it can be adjusted in. The mirror came out of the holder without too much trouble with a bit of help from an allen key poked through the back of the holder.
The finger prints came off quite easily in warm water with a bit of dish washing liquid. After a flush with tap water followed by distilled water the mirror was left to dry standing on its end. The majority of the mirror dried ok but I had to resort to the edge of paper towel to remove a few droplets that remained. I took the opportunity to ensure the secondary wasn't pinched in the holder.
With that behind me I decided to give the primary a swim also as it had three years worth of dust and cats hair on it. With mirrors clean and dry I put it all back together.
I'm really glad I had a laser colimator as it was so far off colimation through the cross-hair colimator that I couldn't tell what I was looking at. I'm now hoping for a clear night tonight for a star test to see if I've goth the mirror clip tension right.
So I've been off to the shop this morning for a bottle of distilled water and cotton wool balls. I can now say I've tried out Starkler's GSO optics adjustment procedure and Iceman's mirror cleaning procedure - thanks to both of you.
I've got to admit that as I removed the secondary mirror I wasn't sure if I was ever going to get it back into the right position given the number of axis it can be adjusted in. The mirror came out of the holder without too much trouble with a bit of help from an allen key poked through the back of the holder.
The finger prints came off quite easily in warm water with a bit of dish washing liquid. After a flush with tap water followed by distilled water the mirror was left to dry standing on its end. The majority of the mirror dried ok but I had to resort to the edge of paper towel to remove a few droplets that remained. I took the opportunity to ensure the secondary wasn't pinched in the holder.
With that behind me I decided to give the primary a swim also as it had three years worth of dust and cats hair on it. With mirrors clean and dry I put it all back together.
I'm really glad I had a laser colimator as it was so far off colimation through the cross-hair colimator that I couldn't tell what I was looking at. I'm now hoping for a clear night tonight for a star test to see if I've goth the mirror clip tension right.