Polar alignment for Eq Mount.

[kimo]

Hi,
I am having problem with star drifting alignment. May be I am too stupid to do so.
How I started.
1: Level the mount and done some Rough Polar alignment alt 1deg and face to North.
2: Balance the mount DE and RA with telescope.
3: Start the motor drive

Alt Alignment:

4: located Star at west and aligned to the center of cross line using motor drive, waited for 5 mints to drift. After 5 mints the star drifted to south so I turned the alt knob to align to center and waited again for 5 mints. Am I doing right? I tried this way three times but it still drifted.

Azm Alignment:

Followed same steps only star chosen at zinith. having same problem.

Thanks.

[orly_andico]

there's an easier way. use a camera.

center the star on the camera (e.g. DSLR). start 30-second exposure. turn OFF the RA drive. after 15 seconds (middle of exposure) turn on the RA drive and press the 2X button.

after the exposure ends you will get a V-shaped line on the image. Tweak the azimuth. Repeat exposure. When you're dead-on polar aligned, the V will become a straight line.

[kochu]

Hi Kimo ,
Try this. It always works for me.
-------------
1. Azimuth adjustment.
Align scope to magnetic north. Turn the scope 180 degrees to face south.(Facing north also should work fine)
Rotate the mount so that the counterweights are at 40 minutes clock position.
Rotate the scope to point 10-15 degrees from zenith and find a star at the centre of reticle.
Stop the tracking and watch star drifting.
Rotate reticle so as to align the movement of star with NS reticle line.
Start tracking and bring the above star to the centre of reticle.
Watch drift.
• If the star drifts up, use the mount's azimuth adjustment knobs to move the mount so that the star appears to move right in the field of view.

• If the star drifts down, use the mount's azimuth adjustment knobs to move the mount so that the star appears to move left in the field of view.
----------------
Alt adjustment
(I do not have to do this as I find the Azimuth adjustment is often good enough, Anyway if you need you can follow the steps below.) .
• Pick a second star in the east, about 20° above the horizon, near the same declination as your first star . In other words, move the telescope mostly in right ascension to select the second star. If there are any obstructions on your eastern horizon, it is possible to achieve an accurate alignment using a star up to about 50° above the horizon.
• Orient the crosshairs again as you did above, so that the horizontal crosshairs are parallel to east-west motion and the vertical crosshairs are parallel to north-south motion.

• Place the star on one of the horizontal lines.

• Let the star drift.
• If the star drifts up, use the mount's altitude adjustment knobs to move the mount so that the star appears to move down in the field of view.

• If the star drifts down, use the mount's altitude adjustment knobs to move the mount so that the star appears to move up in the field of view.

I think in your case the Azimuth and Altitude procedures got mixed up.

Kochu/11-5-11

[kimo]

Thanks for help. I will try it tonight.

[cloud_cover]

IF it doesn't cloud/rain

[timatworksg]

Keep at it Kimo! It can be daunting at first but like riding a bike...u get used to it! Kochu has explained it in a very simply detailed manner!! If something didn't work....try again. PLay around with it...it won't break nor re-set it's system! You can spoil it! Keep playing around and experimenting. It will all come together real soon!!

I am set up aligned South...so standard polar alignment drift is reversed! That was confusing for me at the start as I couldn't grasp why North isn't north when I look into the EP!! haha! Once I got my bearings where NSEW was on my mount....and NSEW was in my EP when I slew....it became clear...lol!