Clean up Telescope lens help

Dear All,

I just received a C8 from a friend, as he don't want to keep it any more.
It was staying in his store room for years. I found that there's fungus
grew inside the front lens. & may be a few spots on the primary mirror.
Can anyone suggest a service centre for me to clean it up?

Thx!

Jo

mca

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發表於 2009-9-8 00:32 | 只看該作者

Probably there is no “service centre” in HK, as most dealers are not favor in “after-sales-service”. As a user, you better learn to clean up C8 yourself. It is not so difficult to do provided you are the kind of DIY:

Basic awareness
1. Take off the front label ring with screwdriver.
2. Mark the glass lens (corrector) with pencil or whatever to identify its orientation, front/back side.
3. Remove the lens and the rim inserts from tube body carefully (not to break the glass !)
4. Clean the lens with distilled water and wip dry with clean cotton handkerchief.
5. Similar thoughts to clean the mirror ....

The rest can be worked out at your own. Remember to put the lens back in original orientation + front/back side. Also the star collimation after repair, which can be done with the 3 set-screws on the secondary mirror holder.

AC

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jojomamani

天文學會會員

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發表於 2009-9-8 08:24 | 只看該作者

Thx! Alan, I know all the dealer in HK is not favor on after service, just thinking about any technician able to help. I did try the way that u're suggested b4. but I found out the lens is firmly stick onto the tube. I dare not force it too much to pull it out. Should I just pul it out strictly?

Jo

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mca

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發表於 2009-9-8 19:02 | 只看該作者

It really needs guts to take the glass plate (corrector) out !

Perhaps you lay some soft & thick buffer material on floor. Have the tube upside down and pull/shake the glass plate out manually with "some" force. I can't say how much the force is. Good luck if the glass not broken.