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Metal shavings in My C11

Started by buzzman, 11/10/2007 02:28PM
Posted 11/10/2007 02:28PM | Edited 11/10/2007 02:28PM Opening Post
I just changed my dovetail bar on my C11 and noticed that after I put the screws back in, there was a small amount of metal shavings on the secondary mirror housing from the screws. My question is, should I be concerned? Any help would be appreciated.
Posted 11/15/2007 06:47PM #1
Robert. Not sure if the C-11 is like the C-8, but the ledge that the corrector sets on does not go all the way around. It has 2 gaps in it. If the C-11 is the same, you may be able to remove the retaning ring, and having a friend or maybe using some tape to hold the corrector in place, tilt the tube down so the shavings will drop down to where one of the gaps are at. You might try a vaccum placed in front of the gap also to assist in removing the shavings.
Just a thought
Posted 11/20/2007 07:17PM | Edited 11/20/2007 07:25PM #2
The best thing is to remove the corrector and clean the shavings if they are more than dust like particles that will float around the inside of the scope. But if they cling to the secondary housing very well leave it alone as performance will not be affected. The corrector can easily be removed and replaced but follow the previous post's cautions. Worse case is the particles stay at the bottom of the scope but the chance of them hitting a the mirror in normal use is very remote. You can also go through the back of the scope where the visual back is and go into the scope that way with double sided tape on a wire to pick up the particles if you have shaken then to the bottom of the scope. Some bending is required as you go through the hole and I would cover the wire with rubber vacume tubing from the auto parts store. Also be careful not to hit the secondary by going in too far with the wire before the bend.

The last method is the trickiest but potentially leaves the scope intact with no alterations (no need to collminate mirrors) but it is very risky.
The first is the best.
For Prevention... always always install screws with the scope above the screws, thread first without the accessory to make sure it goes in smoothly and backing out the screw will let any shavings fall out not in.