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Polar scope alignment.


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I have now purchased my polar scope for my EQ3-2 mount and slotted it into the mount, however, do I need to align it with the mount itself or can I just assume that it goes in without much messing about needed (thats what she said) - if so, how do I get it so its inserted and lined up correctly. Obviously any misalignments here will render any polar alignments made incorrect..

hope that makes sense.

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Yes, you do need to align it with the mount. This is the process:-

Set up the mount on it’s tripod with a rough visual alignment on Polaris by sighting up the body of the mount in the direction of Polaris. Locate Polaris and place it in the centre of the Polar scope by adjusting the Altitude and Azimuth of the mount. Place Polaris directly under the cross in the centre of the reticule. Rotate the mount one half turn about the RA axis. Polaris should remain under the cross in the centre of the reticule. If it doesn’t, the reticule is not centred on the RA axis of the mount and an adjustment must be made. If it is necessary to adjust the position of the reticule, adjust the three screws on the Polar scope.

Make very small adjustments by moving only two of the screws at a time. Adjust the screws to move Polaris half the distance back to the centre of the reticule. This is because Polaris started in the centre of the reticule and by rotating the mount 180 degrees, Polaris moved exactly twice the distance between the centre of the reticule and the centre of rotation. The centre of rotation lies midway between the centre of the reticule and the new position of Polaris.

Do not turn any of the screws more than one-eighth turn at a time. Now re-centre Polaris under the cross in the middle of the reticule using the Azimuth and Altitude adjustments.

Repeat the entire procedure until Polaris remains in the centre of the reticule when the mount is rotated about the RA axis.

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Yup, that's part two! 6 years? Aww, come on it ain't that difficult :glasses1:

If someone was to show me I know I would get it, but trying to convey correctly instructions I have found on the net in to practice has so far eluded me. The instructions I have found require the use of the setting circles and as we all know these are not the most accurate of things. Another one has a program for finding the TDC for Polaris and then rotate the mount according to the date and time. But this again relies on the accuracy of the setting circles. My mount can track for some time but polar alignment isn't bang on enough for any long exposure imaging.

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If it is necessary to adjust the position of the reticule, adjust the three screws on the Polar scope.

Make very small adjustments by moving only two of the screws at a time. Adjust the screws to move Polaris half the distance back to the centre of the reticule.

OK, hit a snag here, I dont have any screws to adjust the polar scope alignment - to fit my polar scope I had to remove the old setting circle assembly which did have a holder with 3 screws and screw the whole polar scope into the end of the mount - I could see no other way of fitting it - so this now leaves me with no way of adjusting the polar scope.. UNless I am missing something here. The polar scope does fit into the mount incredibly snugly but I am just worried that if due to any manufacturing defects of slight machining errors I am going to be a slack alley...

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Glad to see you are all sorted. Good luck with calibrating the finder to the mount :glasses1:

Love this from the EQ6 manual: "There is a radial line in the Polarscope. Along this line, there are tick marks and a circle. Rotate the mount in R.A. until this line points towards Beta-Ursa Minoris"

Ha! - Yup - just throw out those setting circles and crudely point the offset line towards Beta-Ursa Minoris!

They've got a point though - that is good enough for non-photographic purposes, so why do more?

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