CG5 alignment issues

[ryandsimmons]

Hi All,

Just wondering if anyone can point me in the direction of some help in getting my CG5 set up correctly.

Basic was I set up is thus:

1) Set up tripod

2) add weights

3) add on C8 scope

4) Affix camera (EOS1000d) to scope.

5) Set the balance.  (This is not quite as accurate as I was imagining as even with bolts fully loose there is a fair bit of friction, so I have to guess at the sweet spot.)

6) Adjust tripod legs to get spirit level in scope as perfect as possible.

7) Set RA and DEC to arrows pointing.

8) Swap camera with EP.

9) Using Finderscope, and EP align Polaris perfectly in centre of EP.  Using fine RA knobs and adjusting the latitude screw.

10) Plug in tripod.

11) Set up date/ location etc (I am 100% sure these are perfect)

12) 2 Star align (using 8 mil + barlow to ensure as accurate as I can)

13) 4 calib stars

Now I did this on tuesday and when I then swapped out the EP for camera and did 30 second exposures I had good round stars.  There was clear movement between frames, but each individual shot was spot on..  Last night, exact same setup and I had awful trailing.  A 30 second exposure would have trails 3 times the width of a star.  I redid the whole lot 3 times and just could not get anything close.  GOTO would slew to everything spot on, but would not track properly.

I am sure I am missing something here, probably to do with the polar alignment but I cannot see what more I can do?

Any tips?

[hobsey]

Sounds like alignment issues as you didn't mention doing a polar alignment with the polar scope.

[Kirscovitch]

Maybe I'm misunderstanding you, but normally you would align polaris through a polar scop or just the hole running through the axis of the mount. Not aligning it with an EP.

[hobsey]

Align it with a polar scope which goes through the axis of the mount and using an app called polar finder to help you find the position of polaris.

I would post some links to help you out but I'm currently on my phone.

[ryandsimmons]

Ah, I do not have a polar scope.  I just eyeball it through the hole running through the mount, then fine tune using finderscope / scope itself.  I assume that is my issue then?

[Carina Lass]

Undo cap and cover on polar scope

adjust vertical and horizontal mount bolts to align polaris at correct hour angle

check scope points at same place.....

[Kirscovitch]

Ah, I do not have a polar scope.  I just eyeball it through the hole running through the mount, then fine tune using finderscope / scope itself.  I assume that is my issue then?

Once you find Polaris through the hole, fine tune it to the center as best you can with the azimuth and altitude knobs. 

[ryandsimmons]

Hmm... done some more searching and I see I should be able to All Star Polar Align, which may be useful as I do not have a polarscope.

I gather I should:

Do 2 star align.

4 calibration stars.

Polar Align (which will put the scope near a bright star and then I manually move Alt and Azimuth to get the star aligned.)

Given that should now mean i am fully aligned, should I then reset and do a full new 2 star align and calibration?

[Kirscovitch]

All Star Polar Align works well. I've managed 90 second subs on a good night.

You still have to setup the mount as close to North as possible. If you setup too far west or east there is not enough adjustment in the mount to correct it. Line up Polaris through the axis hole as best you can and then do the 2 star alignment. Add as many calibration stars as you can. Then do the ASPA. 

It will ask you to align a star just like in 2 star alignment and when you align it and push enter it will slew away from the star and ask you to center it again. This time however, do not use the handheld to slew the scope. You need to use the azimuth and altitude knobs to guide the star back into the center of the EP. It takes a little practice but when you get it centered hit align and you are now polar aligned.

[Kirscovitch]

Oh forgot to say that If I'm not in a hurry I will power down and restart and align all over again. Sometimes more than once but it is not absolutely needed. In my opinion I seem to get better alignment and if I do it at least twice. 

Makes it all seem worthwhile when I check my handheld for alignment error and it reads 0's across the board. 

[Carina Lass]

yes that 000.00.00 looks kinda wierd but so nice.