EQASCOM Polar Scope Tool

This is really just an update from my post a few days ago about the Atlas Pro AZ/EQ-G mount and the new software we've been trying out to get everything up and running. I did not mention Alignmaster because we simply could not get it to work correctly. I'm still not sure if this is because of user error or not but we have found something else that seems to work great.

This method does require that you have a view of Polaris (for Northern Hemisphere users). When using a polar scope it is very important to place the RA axis of the mount precisely where Cassiopeia and/or the Big Dipper appears in the sky. This can be really difficult to judge sometimes and usually it is just a guess. EQASCOM and Chris Shillito of the EQMOD Project has come up with a simple solution.

I wont go through the routine here, but will say it is very easy and it just works. After going through this simple procedure the guiding graph in PHD2 looked much improved compared to just eyeballing it. It seems to be very precise. Here's a screenshot of the graph after aligning the mount with this method.

Here's another after making a few small adjustments. The mount only required that very small corrections be issued from PHD2.

These were done with the 80mm f/6 apo, the next night out we tried guiding the 8RC at 1600mm focal length and it performed great. Looking forward to getting my camera back from SBIG and putting it all to work.

For complete details on using this method please see Chris' video.

Detailed written instructions can be found here:

http://eq-mod.sourceforge.net/docs/PolarScopeAlignment.pdf

Atlas Pro AZ/EQ-G

I managed to get several images with the CGEM DX mount over the last 2 1/2 years. Some pretty good, some not so good. It was just very unpredictable, and I started saving up some money and sold the AT8IN telescope to help fund a new mount.

There were several that I had my eye on. The new iOptron CEM60 EC seemed to be a very nice mount. The Losmandy G11 has been trusted for years and has recently been refined with the release of the Gemini 2 hand controller. Both of these mounts will carry a maximum payload of 60 lbs and looked appealing. The new Orion HDX110, which is the Skywatcher EQ8 with the Orion name, also looked very nice with its capabilities of handling up to 110 lbs of weight.

There are a few things I'd still like to buy for my astrophotography hobby. I still need to get the Astrodon OIII and SII narrowband filters. I would also like to automate my focusing with motorized Moonlite focusers on my telescopes. And I would like a nice 110-130mm apo triplet to have for visual use, as well as fill the void in my imaging line of scopes left from selling the AT8IN. Its a pretty big jump from the 480mm focal length of the 80mm triplet up to the RC's 1150mm focal length using the CCDT67 Telecompressor. So I'd really like something in the 700-800mm range.

After weighing my mount options with my wants/needs, I decided to settle for a smaller mount. The new Atlas Pro shares a few features of its big brother, the HDX110. They both use the same Altitude adjuster that is much smoother than most mounts on the market. They both use belt driven stepper motors with dual encoders. And they both use closed-loop electronics which allows you to manually move the scope, or rebalance, without it loosing its alignment. The Atlas Pro AZ/EQ-G it would be!

I ordered the new mount from Orion and it arrived in two boxes about a week later. When I set up my pier last year I removed the mount adapter from the top of my CGEM DX tripod and fabricated a way to fasten it to my pier plate. I was hoping it would work with my new mount. The metal post for adjusting azimuth was too long for the Atlas Pro mount, but it was as simple as removing the CGEM DX post and screwing in the one that came on my Atlas Pro tripod. It fits!

This picture shows the mount set up for my 80mm triplet. For larger scopes, the mount also comes with a counterweight bar extension and another 11 lb counterweight.

 The mount is so quiet when slewing! I just had to remove the cover to check out the stepper motors and drive belts. This is a really nice system and much better than gear-to-gear in my opinion. In addition to being quieter the backlash is also significantly reduced or eliminated. There is always some backlash in any gear-to-gear system.

This is a close up of the "Captain's Wheel" DEC clutch. The small t-bolt under it allows the counterweight shaft to retract up inside of the mount for easy transporting and storing.

Here is the RA clutch and just below it is the illuminated polar scope. The brightness of the illuminated scope can be adjusted with the hand controller.

This is the adjustment for altitude with the handle retracted. It is much smoother than the other equatorial mounts I have used. Below it is shown with handle out ready for adjustment.

I have not been able to really use the scope yet for imaging, but I am confident that this will be an excellent mount for astrophotography. The very first night, we did a rough polar alignment using the polar scope and did a little autoguiding and it performed great. Here is the PHD graph with no adjustment of the PHD2 settings and the rough polar alignment. I am sure with a more refined polar alignment and some fine tuning in PHD this will get even better.

One big reason I wanted to go with this mount is that it is supported by the EQMOD Project. I have read great things about EQMOD and EQASCOM and wanted this program for controlling the mount/telescope. It really is a well thought out program with excellent capabilities. I am still trying to learn more about it but everything so far has been positive. I will report in more detail about EQASCOM as soon as I feel comfortable using it and learn more about it. Please check into it yourself to see if your mount is supported. If so, I think you will really like the program. I did purchase the recommended interface cable from Shoestring Astronomy for connecting the mount to the computer. For the Atlas Pro AZ/EQ-G this cable is the USB2EQ5. For regular Atlas owners this would be the USB2EQ6 interface cable.

For aligning the mount for goto you can make a pointing model using several stars. Usually just a star to the west and one to the east will be good enough for casual goto performance. This is great for observing but with Elbrus plate-solving software its not really needed at all for imaging.

I should also mention another piece of software that is very important. With the interface cable from Shoestring Astronomy, you no longer use the hand controller. EQASCOM controls your mount but you'll need something else if you want goto capabilities. Stellarium is great for this but I found that it was too much of a memory hog for my old desktop that I have in the observatory. I found a free program that others are using called Cartes du Ciel. So far it has worked great and seems to be a nice program.

Just select a point on the sky chart to get coordinates for your plate solving software or select slew for goto. With tracking enabled it will track where your scope is pointing on the sky chart.

By this time next month I hope to have a few images under my belt using the new set up. Hopefully by then I can report a lot more on the new software and the performance of the new mount. I believe that the Atlas Pro AZ/EQ-G will be a wonderful addition at Little Piney Observatory. Clear skies everyone!