Aligning CGEM 925

[KaiserBill]

So. I obtained my 925 a few weeks ago. I set it up, placed the CGEM to the index marks, did my first automatic slew to Deneb and the scope pointed to the other side of the meridian. I checked; right time, right date, eastern standard time,correct place...so I centered it in the finderscope, pushed enter, and then placed it in the middle of the eyepiece, and pushed align. Next I did a second star. This time the first slew the telescope did was basically pointing at the ground. I went through the above machinations again. I did a third star. Then tested it on Jupiter. It was at least on the correct side of the sky. It was pretty far off for andromeda too.

Ant ideas?

Thx!

[brantuk]

Hi KB and welcome to SGL.

Did you polar align the mount first? An equatorial mount should always be set to point at the pole star before switching on and doing a star alignment. Some mounts also have GPS - if your's does then give it 10-15mins after switching on so it has time to pick up 3 passing satellites and triangulate it's position on the Earth. If you don't have GPS then lat/long need to be set manually and accurately. Hth

[KaiserBill]

Hi Brantuk,

Thanks for your response. I did NOT polar align it. I pointed it north and had the proper latitude cranked in (43.9). I wasn't certain if it was critical to have the North Star sighted in the 'tube'. I will tonite!

[Steve Ward]

Undoubtedly an incorrect data input somewhere , check the date format ( MM/DD/YY ) and your location details are put in the correct way round. Details will be in the manual ... 

[KaiserBill]

Steve; thanks. I've been going over and over the whole procedure. As far as I can tell it's all entered correctly. I'm wondering if I might have the tube on backwards! At least to my eye it's not obvious what is front and back on the tube mount.

[gnomus]

Steve; thanks. I've been going over and over the whole procedure. As far as I can tell it's all entered correctly. I'm wondering if I might have the tube on backwards! At least to my eye it's not obvious what is front and back on the tube mount.

I have a CGEM.  I think it is important to be able to see Polaris through the central tube, or your polarscope if you have one.  I usually do the two star alignment routine and then add three calibration stars.  It is usually pretty close at the end of the two-star procedure, and is bang on by the second calibration star.  

Perhaps you could talk us through your alignment and calibration routine.  I'm not sure I followed what you did.  You mentioned doing an "automatic slew".  Did you go through the two star alignment routine?

Regards 

[gnomus]

Steve; thanks. I've been going over and over the whole procedure. As far as I can tell it's all entered correctly. I'm wondering if I might have the tube on backwards! At least to my eye it's not obvious what is front and back on the tube mount.

Sorry.  Just read this bit properly.  When you have set up the mount (but before you attach the weight and the scope), and with the mount in the home position, the weight arm should should be pointing Northwards (but towards the ground, of course).  If you rotate the bracket that holds the scope by 90 degrees and take off the end caps on the mount, you should be able to see Polaris through the hole.  You may need to adjust the mount to get Polaris as central as possible.   Go back to the home position.  Only then do you put the weights and scope on.   The scope will be pointing up in the air (again generally looking Northwards, although it will not be looking at Polaris).  

When I do my two-star alignment at the moment, the first star the mount usually wants to go to is Vega. (I'm in the UK though and don't know if that would make a difference.) 

[brantuk]

One other thought - is it set for "EQ North" - if it's new they usually come pre configured for the Northern hemisphere - but worth checking in case it thinks it's in the Southern hemisphere. Also ensure you don't have any unreasonable slew limits inadvertently set.

Oh... and check you have sufficient power - I've had Celestron mounts that suddenly go crazy (for no apparent reason) when the power drops below 12V.

[KaiserBill]

Folks,

Thanks for your advice.

I found how to fix whatever the issue was.

I called the friendly folks at Highpointscientific in New Jersey, where I purchased my 925. The gent told me to go under utilities and initiate 'factory reset'. The payback here is that you must re-enter all your position and time data. Not a big deal.

I did it , twice, as recommended. So last night I set the Beast up, just did a Quick Align, keyed in Mars, and bingo, there was Mars. It was six below zero (F) and windy so I fled indoors immediately after viewing the spectacular Orion Nebula, AND the Lovejoy comet.

I'm relieved the device functions. Tonight I will use Quick Align again then add stars I can easily view!