Tutorial on how to Polar Align using EQMOD's Polar Alignment tool.
In this tutorial I want to show how to perform Polar Alignment using EQMOD's polar alignment tool. This method, if done precisely, can get you to a very good Polar Alignment without a need to Drift Align after that. Telling from my experience, I don't Drift Align anymore, as I want to leave small drift to battle the Dec backlash and using EQMOD's tool only just give me that. Then using PHD2 and Resist Switch algorithm I can shoot 15 minutes frames on 2000mm FL without any problems on my EQ6. The important thing is to properly calibrate the mount with EQMOD and you are ready.
To calibrate our mount with EQMOD we would need an a distant object. It doesn't have to be at night and could be done in the daylight.
As always, I start with leveling the tripod accurately. Then I place the head, turn DEC axis 90° and move it so I can see the object in the Polar Finder.
Then using Alt/Az bolts of the mount, we bring our distant object exactly to the cross.
Next, we need to set our initial position from which EQMOD's tool will calculate the actual position of the Polaris. The initial position can be set at 3, 6, 9 and 12 o'clock. In my case I noticed, that when RA axis in Home Position, the Polaris's bubble very close to 12 o'clock. Since later we would need to move the bubble, I decided that my starting point would be set as 12 o'clock.
Now, using only Altitude bolts of the mount I bring the distant object straight up from the cross, until it reaches the larger circle, as shown in the image.
The next step is the actual calibration.
At this point you should power up your mount and connect it to EQMOD. It is also important that you will set your RA and DEC axises to a Home Position. Since in the field you going to start from Home Position, you should also have to set to it now.
I will also advise to use Gamepad instead of mouse, because it's so much easier to control the mount while watching through Polar Finder.
When in Home Position, the DEC axis obscuring the view and we cannot see our object (or Polaris while Polar Aligning), so the first thing we need to do is to rotate it 90°. Unpark the scope and using your gamepad or mouse Rotate it 90°.
After we have rotated our DEC axis, now we can see through the Polar Finder and see our object.
The next step, using ONLY Gamepad or mouse we need to rotate the RA axis and bring the bubble to 12 o'clock, exactly over the object which we left there on the large circle.
And if you want to be more precise than doing it with the eye, as mentioned in previous tutorials, the bubble in EQ6 Polar Finder is exactly one hour wide. So you can use the RA hour scale to put the object exactly on the middle.
After we had rotated both of our axises and aligned the bubble exactly on 12 o'clock we need to tell EQMOD that this is the Polar Scope Home position, from which later it will align to the actual position of Polaris.
On the site information area, click on the "Clock" tab next to Polar Star HA. This will open the Polar Scope Alignment Tool. Since I moved bubble to the 12 o'clock position I will also choose 12 o'clock from the dropdown menu. Then click on the button with + and House to save the PolarScope Home position.
That's it, we have calibrated our mount and EQMOD Polar Alignment tool. Now you can Park the scope and it's ready to be used under the stars.
So when I'm under the stars I'm always do 3 things carefully, level the tripod, balance all the equipment and set mount to Home Position. That way, everything that I marked/calibrated at home, would be exactly the same when I setup in the field and headaches would be lessen.
After setting up the mount we powering it up and launch EQMOD. Enter you Latitude and Longitude according to your observation site or use GPS devise to read the coordinates out.
1. Unpark the scope
2. Click on "Clock" button to open Polar Scope Tool.
3. Click on the button with "arrow" and "house" - Move to PolarScope Home.
After clicking on that button, the mount will perform movement exactly as we teach him in the steps before. It will move to the Polar Scope initial position, when DEC axis will be turned for 90° and RA axis will align the bubble to the 12 o'clock.
4. Click on Align Polar Scope button and PolarScope tool will align your RA axis exactly to the position of the Polaris in the sky according to the time and coordinates of your observation site.
After alignment, EQMOD initate Tracking, so you can adjust your mount and bring Polaris to he's bubble with no rush.
You have to be very carefull with all the equipment and wires running around your mount. Double and triple check that nothing going to smash on one of the legs when mount moves !!! Keep your hand on STOP button while mount moving !!!
One last reminder, is not to bring the Polaris exactly to the center of the bubble, but closer to the inner side of the circle.
This method not going to replace the Drift Alignment, but performing it precisly and carefully will get you very close.