On this tutorial I will explain how to build simple tool and use our mount as a measurement instrument to perform Polar Alignment when we cannot use Polar Finder scope. Of course using Drift Alignment method is way superior, but when East and West not visble, that is another way to do it.
As I have mentioned above , we going to use our mount as an instrument and bubble level tool, so starting with perfectly leveling the tripod is advisable.
Next step we would need to build a simple tool. It could be made of some hard materials so it won't bent under it's own weight, but I have used hardbox piece and it did the job. 30 cm (12 inch) of length is enough.
Next I going to cut it the width of my compass so it can lay on it.
Knife, scissors, it all works.
That is how it looks like after cuttings.
Next, I'm going to measure the north pin of my mount.
Measuring both sides shows that it's completely square.
Next we going to cut out the measured square on the piece of hardbox. Make sure that the sides of the opening would be precisely parallel to the sides of the hardbox piece.
Like this.
On the opposite side we attach the compass.
Now, after placing our tool on the leveled tripod, all we need to do is to roatate the tripod so the compass show exactly to the north.
Now we going to place the mount's head on the tripod. Since our north pin sides should be pointing north, we adjust Azimuth bolts equaly on both sides, making sure that the mount's head would also point to the North.
(There is also an option to perform Drift Alignment. For example from my balcony I don't have East, nor the West open, just South. So instead of relying on the length of bolts I can perform Drift Alignment close to Equator and Meridian cross.)
Now we need to reset our DEC scale to zero so we can use it as a measurement tool next. But before, make sure to put RA axis into Home Position, meaning that counterweight shaft would point straight down.
Put the bubble level on the DEC saddle and make it level by turning the DEC axis.
After leveling the DEC axis we need to set the scale to 90°.
This is how it supposed to look like. Exactly 90°. When we turn DEC axis to it's home position, the triangle mark would read 0°.
Next step we going to align our mount to the Latitude of the place we are observing from. For example, the Latitude of my home is 31° 58". So I'm going to round that number to 32° and turn the DEC axis so, that it would aslo read 32°.
Like this.
Now we need to turn RA axis exactly 90° and we need carefully to level it, by placing bubble level on the counterweight shaft. Engage the RA clutch.
Now, while mount in this position, we going to place the level on the DEC saddle and check it out.
In my case, I have a Losmandy style saddle, so it have square corners. But if you have original , round saddle and can't place the level on it, you can use your scope, placing the level on the lid. Level have to be placed in perpendicular position to DEC axis. As shown in the image.
In the next step, we going to use only Altitude bolts of the mount and adjust them while watching the level bubble. When you'll level it out, your RA axis will be parralel to the Earth's axis and you'll be very close to be Polar Aligned.
There is another thing left to do after all of the steps above. I turn the mount on and feed the handset with all the current data and proceed to Star Alignment procedure. Now when I perform very first GOTO of the star alignment, the handset software assumes that we start from perfectly Polar Aligned position and also from Home Position of the mount, so the first GOTO should be somehow precise. Then I let the mount to slew to a choosen star and check for it with the illuminated reticle eyepiece. It would be off of course and might not be even in the view.
Then I use Alt/Az bolts of the mount to bring the star to the field of view.
After physicaly moving the mount to bring the star in the field, I use handset controlls to center it in the eyepiece and then complete the star alignment with available stars.
This method won't let you to image DSO for long exposures of course, but from my experience it's enough for a planetary work and mount tracks the objects very well.
