Re: Received my new EXOS-2GT #EXOS2 #ExploreStars

Steven Romero

Thanks Kent!

That polar scope alignment procedure needs to be posted on the website.

So far I like the products and the customer service is great! But the documentation on the scopes and mounts is pretty thin.


On Mon, Jun 1, 2020 at 4:03 PM Kent Marts Explore Scientific Customer Service <kent@...> wrote:



Here’s a draft document I’ve written.


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This process outlines how to align the illuminated polar finder scope (SKU PFEXOS2) found in the polar axis with the polar axis of the EXOS2GT mount, whether or not the mount comes with the PMC-Eight motion control system.

To get a close polar alignment, the polar finder scope must be aligned with the polar axis.



This process is easiest to do without a telescope or the counterweights installed. Leave the counterweight shaft attached because it makes a good handle at a certain point.

With the EXOS2GT tripod set up outside, orient the polar axis with a fixed that is as far away as you can see – a telephone pole, a radio antenna on top of a mount, a prominent tree: Miles is better than 500 yards.

Adjust the tripod height so that when the polar axis is lowered to align with the target object the illuminated polar finder eyepiece is in a comfortable viewing position. Usually this is done while seated.

Remove the polar finder scope eyepiece cover and the screw-in port cover. Rotate the declination axis 90 degrees to open the internal viewing port.

Use the azimuth knobs and altitude control to adjust the polar axis until you can see the prominent object you selected in the illuminated polar scope.

The center of the illuminated polar finder scope is marked by a cross. That marks the Celestial Pole.

Make fine adjustment to the azimuth and altitude to get a specific part of the target object lined up with the Celestial Pole mark. Example: The top of a radio tower.

Unlock the Right Ascension and rotate the head around the polar axis – best accomplished by grasping the counterweight shaft. As it turns, watch the movement of the Celestial Pole mark. If it simply rotates and stays on the target object, then the device is perfectly polar aligned. But if it moves away from the target object as the RA is rotate, it is NOT aligned.

When the Celestial Pole mark is rotated until it’s as far away from the starting point as it can get, stop rotating it and lock the RA axis.

Now it’s time to adjust the illuminated polar finder scope. On the scope is a collar with three Allen screws. These screws adjust where the device points.

NOTE: The three-screw system requires tightening one screw and loosening two in order to keep the system tight.

Using the correct Allen wrench, look through the illuminated polar finder then slightly turn a screw – just pick one and start. After determining how that Allen screw affected the illuminated polar finder, try another screw. Through trial and error you will determine which screws need to be turned to move the Celestial Pole toward the target object.

When moving the Celestial Pole marker, only move it half way back to the target object. DO NOT move it all the way back.

With the Celestial Pole mark halfway back, use the azimuth adjustment and altitude adjustment to move the mark the rest of the way back to center it on the target object.

Unlock the RA and spin it around. At the point that it is farthest away from the target object, lock the RA.

Use the Allen screws to move the Celestial Pole marker back HALF WAY back, then finish moving with the azimuth and altitude controls.

Continue this process until the Celestial Pole marker stays in the same place when the RA spins.

The illuminated polar finder is now collimated with the polar axis of the telescope.



Kent Marts

Customer Service

Explore Scientific


From: <> On Behalf Of Timothy Myers via
Sent: Monday, June 1, 2020 12:25 PM
Subject: Re: [ESPMC-Eight] Received my new EXOS-2GT #EXOS2 #ExploreStars



I also found that I could sit in a chair and sighting through the Polar Scope was not a big issue. I ended up making marks on my driveway that helped get the mount close to the same spot each time I use it, and then started using Sharp Caps Polar Alignment tool. I have not had to site through the PA Scope in three or four months, since starting with Sharp Cap. 

I did notice however a couple weeks ago that my Polar Scope had come loose, internally. Had to remove it and tighten things up, which means I need to re-align it. i could easily do that after setting the scope up one evening, but I keep forgetting to do it. Have you done a good alignment of your Polar Scope?
Tim Myers

Telescopes:     Celestron 4SE, Celestron 8SE, SkyWatcher 100ED Pro
Mounts:           4-5 SE, 6-8SE, EXOS-2GT with PMC-Eight
Cameras:        ASI1600MC, Cooled
Tablets:           Asus Nexus 7, Amazon Fire 7
Laptop:           Lenovo

Kent Marts
Customer Service
Explore Scientific

Gear: Anything in the store!

Steven Romero
Location: SE Texas
Mount: EXOS2-GT PMC-8
Scope: ED102 APO

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