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Polar Align Scope Wobble

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#1 dedoky

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Posted 21 June 2009 - 11:43 AM

Im trying to align the polar scope to the mount and the closer I get the crosshairs to stay centered on my target while rotating the RA axis, the more the whole view through the polar scope starts to wobble around. Im using a new Skywatcher EQ6 and have been following Astro Babys guide. Any ideas what would cause this? Is it normal?

#2 John Carruthers

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Posted 21 June 2009 - 12:59 PM

Sounds like the reticle is eccentic, have a look at Alan's polar how to

#3 astro_baby

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Posted 22 June 2009 - 01:20 PM

Hi,

Can you describe the falut a bit more. When you say the view 'wobbles' do you mean there is motion in the view OR that the crosshairs become progressively worse in alignment to the target ?

Firts thing to check is if the polarscope is seated formly. Can you rotate the polarscope tube at all or it its screwed down tight into the mount ? It should be quite tight. When new mine was almost solid and I had to use mole grips to take the polarscope out with when I stripped the mount down. If its hand tight that should be enough.

#4 dedoky

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Posted 22 June 2009 - 01:42 PM

The problem is the whole view wobbles, even when the crosshairs stay centered on the target. I used to think that the adjustments moved the actual polar scope but have learned it just moves the crosshairs. So my guess is the scope itself is misaligned. Last night I managed to get perfect round stars while imaging at 800mm for 30s so the wobbling view may not be a problem.

#5 Gunner

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Posted 22 June 2009 - 02:39 PM

I had a SVP that did the same thing, you will need to adjust the set screws in the polar scopes tube.

Here's the tutorial I used the process took about 45 minutes and once it was done I had no more problems.

The tutorial is for the SVP but I'm sure it will work for the Skywatcher.

http://www.andysshot...nmentScope.html


Good luck


Allen

#6 hudson_yak

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Posted 22 June 2009 - 02:48 PM

So my guess is the scope itself is misaligned.



Yes, that's exactly what it means, the tube itself is not parallel to the axis. You can compensate for this like you have, by adjusting the crosshairs, and it'll work ok, just looks a little odd to have the whole view moving around when rotating.

I'd try to assess why the tube might be in there crooked, though, as it could mean it'll get jarred out of position more easily. Given the mounting method it probably can't be made to be prefectly on axis, but fairly close should be possible.

Mike






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