Thread: Polar Alignment
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Old 21-07-2007, 10:23 AM
Zuts
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Zuts is offline
 
Join Date: Mar 2007
Location: sydney
Posts: 1,837
Hi All,

A bit dissapointing. I managed to get it sort of aligned, enough to do a 3 minute exposure but it took me hours and hours. The next night i tried again and thought it was polar aligned but when i turned on tracking it just wasnt. I guess I have to rethink.

Here is my procedure, are there any glring problems with it?

Initial
(1) Get fork arms pointing roughly south at roughly 34 degrees.
Azimuth
(2) point scope at intersection of meridian and equator. OTA at right angles to fork, fork arms horizontal.
(3) Align reticle so left/right/up/down on controller matches reticle lines.
(4) ensure have enough play on the wedge. By hand move wedge all the way left and then then all the way right. At each end ensure that star moves a different direction. Up at one end, down at the other. Then center the wedge.
(5) turn off tracking so i can pick up drift quicker.
(6) Find any star in the reticle within a few degrees of the meridian/equator intersection.
(6) watch for up/down drift and use the azimuth wedge controls to adjust accordingly until the star does not drift up or down any more. As the star drifts from one side to the other use hand control to move it back to the other edge. If there is no up or down drift for at least 10 times accross the FOV of the reticle then assume polar aligned in azimuth.
Declination
(7) with the ota aligned on the equator, rotate towards the east to about 20 degrees above the horizon. This is difficult as there is a big tree so i am probably 5 or 6 degrees off the equator.
(8) repeat step (3)
(9) find a star in the reticle within a few degrees and repeat step (6) with the declination wedge controls.

Finally repeat all the above for both axes to fine tune.

When in Azimuth the wedge/tripod bolts are loosened but when i do dec i tighten everything up.

Anyway i did all the above and then turned on tracking and did a two star align and i was nowhere near polar aligned as i got star trails after about a minute.

So i am very confused. Maybe doing the 2 star align (which is all the hand controler allows) which has the scope pointing at very funny directions caused the wedge bolts to loosen, i dont know but i guess i will try again.
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