Image of the day

Captured by
Byron Davies

M-20 Trifid Nebula

My Account

New to Astromart?

Register an account...

Need Help?

fix for mirror flop in an older C8?

Started by glennd, 06/16/2005 08:52PM
Posted 06/16/2005 08:52PM | Edited 06/16/2005 08:58PM Opening Post
hi all,
i use an older C8 for imaging. i'd like to find a way to limit mirror movement. the mirror moves relative to the tube when scope is moved significantly. i solved a similar problem on an older meade sct using the mirror lock screw hole provided for shipment. the C8 doesn't have such a provision and i'm wondering if anyone out there has found a good solution. i could take the scope apart and see if i could make the same holes the meade has, but wonder if there is a better idea out there.
thanks,
glenn
Posted 06/16/2005 10:31PM #1
I also have a C8-gray ota and am getting started in imaging. My ota has noticable mirror flop. My solution was to pick up a motofocuser that attaches to the ota at the v-back. It's an older NGF-S w/moto by JMI, got it in an auction. wink At a great price. I didn't like the motofocusers that attach themselves to the normal focuser knob and there by moving the mirror.

I can coarse focus with the normal knob. Then fine tune with the motofocuser. The added plus is no mirror movement and little or no vibration. I know there are non-motor focusers out there that attach to the v-back and provide the same type of results, by fine focusing at the v-back and not moving the mirror.

Don 8)
Posted 06/17/2005 11:39AM | Edited 06/17/2005 11:40AM #2
Glenn,
It's funny you should post this question now. I have just finished an article for the "how-to" section of astromart. In the article I explained how to reduce mirror flop. I had done this to my SCT and pretty much eliminated the problem. It does require you to remove the corrector though. Check out the article, I think you'll find what your looking for.

http://www.astromart.com/articles/article.asp?article_id=271

Clear skies,
Jay