HOW TO ACCURATELY ACCOMPLISH POLAR ALIGNMENT
The “declination drift” method is the most accurate way to accomplish this. The method is pretty straightforward, but it does require some time and patience.
I first saw this in print in an article in Astronomy Magazine titled, “Perfect Polar Alignment.” I could not find it online, but while searching, I found this:
https://skyandtelescope.org/astronomy-resources/accurate-polar-alignment/
The process is the same.
First, aim the mount’s polar axis roughly at Polaris.
Now point the telescope at a star that’s on or near the celestial equator and as close to the meridian as you can judge.
Put in a high-power eyepiece. If the eyepiece has cross hairs, (preferred) center the star on them.
Rotate the eyepiece so that the crosshairs are aligned N,S,E,W. [A star centered in the field will exit the field at the west point of the field. Or … If using a variable speed drive system, you can slew the scope back and forth E-W so that the star tracks the E-W line of the crosshair].
Ignore any east-west drift.
If the star drifts south in the eyepiece, the polar axis is pointing too far east. Move the polar axis west by using the mount’s azimuth adjustment.
If the star drifts north, the polar axis is too far west. Move the polar axis east by using the mount’s azimuth adjustment.
Shift the polar axis left or right accordingly, until there is no more drift. This is where the patience comes into play.
Initially, the direction of the error will likely be apparent in only a few minutes. As corrections are made, the amount of time required to detect the drift will increase. If the direction of the error reverses … you’ve gone too far with the azimuth adjustment.
Now, the process is repeated while tracking an equatorial star that is near the eastern horizon.
If the star drifts south, the polar axis points too low. Raise the polar axis with the mount’s latitude adjustment (GEM) or the altitude adjustment (wedge).
If the star drifts north, the polar axis points too high. Lower the polar axis with the mount’s latitude adjustment (GEM) or the altitude adjustment (wedge).
Again, shift the polar axis accordingly up or down.
Now go back and repeat from the beginning, because each adjustment throws the previous one slightly off. When all visible drift is eliminated the telescope is very accurately aligned.
I used a 12.5mm double crosshair illuminated reticle orthoscopic eyepiece.
Relatively high power - 285X.
I spent two nights in 2006 refining my alignment and I check the alignment annually using this procedure. I have needed no further corrections since. I see no noticable drift (at 285X) after 30 minutes of tracking. Since I am 100% visual, this is much better than it needs to be!