Return to the Cloudy Nights Telescope Reviews home pageAstronomics discounts for Cloudy Nights members
· Get a Cloudy Nights T-Shirt · Submit a Review / Article

Click here if you are having trouble logging into the forums

Privacy Policy | Please read our Terms of Service | Signup and Troubleshooting FAQ | Problems? PM a Red or a Green Gu… uh, User

Equipment Discussions >> Mounts

Pages: 1 | 2 | (show all)
wolfman_4_ever
Pooh-Bah


Reged: 07/15/11

Loc: El Segundo, Ca, So. Cal
Re: Okay, I'm baffled...CG5 tracking issue new [Re: Dwight J]
      #5475838 - 10/17/12 08:41 PM

It looks like you are using the stock CG5 saddle and a Vixen style dovetail..

I kinda had my cables ran the same way except I tied them off on the OTA handle. Only while pointing in the east and at about 45-75 degrees. I would be dead center then over a period of about 15sec I could watch the mount shift and the picture shift in the live view. If I grabbed the wires and lifted them up to reduce gravities effect, the issue would stop. As soon as I let go, it would start again until the slop was tight again.


Post Extras: Print Post   Remind Me!   Notify Moderator  
Tom Andrews
Pooh-Bah
*****

Reged: 01/25/07

Loc: Albuquerque, NM
Re: Okay, I'm baffled...CG5 tracking issue new [Re: Dwight J]
      #5475964 - 10/17/12 10:07 PM

Quote:

In addition to the actual mounting points of the dovetail flexing ( your image reminded me of what differential flecked looks like), the dovetail may not be snugged up or has a slight tilt. When I mount my OTA the dovetail is horizontal. More than a few times it has not been tight all the way or crooked. I now rotate the tube around the dec axis 180 deg after attaching it to check for this slack. Another scope I use has the Losmandy style dovetail and mounts solidly but is a pain to slide on.




Dwight,

More good points. I am very careful when mounting my OTA's because I have read here about others' sliding off the mount. So I double and triple check that the dovetail bar is sitting in saddle correct.

Now if the dovetail is flexing, hummmm...


Post Extras: Print Post   Remind Me!   Notify Moderator  
Tom Andrews
Pooh-Bah
*****

Reged: 01/25/07

Loc: Albuquerque, NM
Re: Okay, I'm baffled...CG5 tracking issue new [Re: wolfman_4_ever]
      #5475994 - 10/17/12 10:23 PM

Quote:

It looks like you are using the stock CG5 saddle and a Vixen style dovetail..




Correct.

Quote:

I kinda had my cables ran the same way except I tied them off on the OTA handle. Only while pointing in the east and at about 45-75 degrees. I would be dead center then over a period of about 15sec I could watch the mount shift and the picture shift in the live view. If I grabbed the wires and lifted them up to reduce gravities effect, the issue would stop. As soon as I let go, it would start again until the slop was tight again.




I was tying my cables to the OTA handle too until I used the 5" Mak which doesn't have a handle. I used the Mak enough that I got out of the routine.

Next time out I will set up my normal way then try lifting the cables up to see if it makes the difference. Thanks again for offering this info, I might never have thought about it because the 5" and 11" work with the cables as is.


Post Extras: Print Post   Remind Me!   Notify Moderator  
Tom Andrews
Pooh-Bah
*****

Reged: 01/25/07

Loc: Albuquerque, NM
Re: Okay, I'm baffled...CG5 tracking issue new [Re: Tom Andrews]
      #5479177 - 10/19/12 05:35 PM Attachment (11 downloads)

Okay, I took the screws loose on the dovetail bar and retightened them to the point of stripping the sockets.

I rechecked my balance again.

I rerouted my cabling slightly to take any weight off the camera, let me know if I should be doing something different.

Last night I tested both the Meade 8" and the Mak 5"; both had the same problem. I tried holding the cables during integrations and moving them to different positions. There was no difference no matter what I did. I also tried different points in the sky to see if horizontal was better than vertical or if the motion was different. There was no difference for altitude. The motion goes from right to left across the screen when pointed West and bottom to top when pointed East; that should indicate something or at least rule something out.

I recorded video from both scopes to show what's happening. I'm adding links to them on YouTube. I paused the recording for the bulk of the 56 second integrations so I could get the motion of 4-5 integrations in a short video. I also did one at 28 seconds to show the same problem. On the one of C14 I forgot to change the notes on the screen and it shows M27 so ignore that.

I realize that in any hobby user error accounts for probably 99% of the issues and it would seem logical that my problem is just that. If the 11" scope had the same problem then it would be concrete but it works to the limit of CG5 tracking. And it has worked consistently everytime where the other 2 scopes have consistently NOT worked everytime. Apparently no one else is having this problem and there are who knows how many CG5's out there with every size of scope possible. So any other suggestions would be much appreciated.

M27-Mak 5"-Integration 56 seconds
C14-Mak 5"-Integration 56 seconds
C55-Mak 5"-Integration 56 seconds
M27-Meade 8"-Integration 56 seconds
M27-Meade 8"-Integration 28 seconds

Edited by Tom Andrews (10/19/12 05:45 PM)


Post Extras: Print Post   Remind Me!   Notify Moderator  
rmollise
Postmaster
*****

Reged: 07/06/07

Re: Okay, I'm baffled...CG5 tracking issue new [Re: Tom Andrews]
      #5479263 - 10/19/12 06:29 PM

Look to the GEM head tripod connection next.

Post Extras: Print Post   Remind Me!   Notify Moderator  
Tom Andrews
Pooh-Bah
*****

Reged: 01/25/07

Loc: Albuquerque, NM
Re: Okay, I'm baffled...CG5 tracking issue new [Re: Tom Andrews]
      #5491815 - 10/27/12 02:59 PM Attachment (10 downloads)

Quote:

I realize that in any hobby user error accounts for probably 99% of the issues and it would seem logical that my problem is just that. If the 11" scope had the same problem then it would be concrete but it works to the limit of CG5 tracking. And it has worked consistently everytime where the other 2 scopes have consistently NOT worked everytime. Apparently no one else is having this problem and there are who knows how many CG5's out there with every size of scope possible.




Success! As mentioned above, the problem was user error. I finally tried ALL STAR POLAR ALIGNMENT at the recommendation of my brother and what do you know, it works! I still don't know why I got 80 second integrations through the 11"...

Here's a snapshot off the screen from last night, no processing other than Gamma, Contrast and Brightness on the Debut capture software I'm using. This one was 150 seconds (2-1/2 minutes) and showed signs of tracking error but very little. I'm not an imager per se, just interested in live viewing so this error at 2-1/2 minutes is completely acceptable. This image isn't very good but since it was through a 5" Mak with 89% moonlight and no filters, I couldn't be happier. Next item on the shopping list are LP filters.

Thanks again for all the helpful suggeestions of which I tried every one.

(Edit: I just noticed I had M31 in my notes for the image, obviously that was another user error!)

Edited by Tom Andrews (10/27/12 03:03 PM)


Post Extras: Print Post   Remind Me!   Notify Moderator  
Pages: 1 | 2 | (show all)


Extra information
21 registered and 37 anonymous users are browsing this forum.

Moderator:  Dave M, richard7, bilgebay 

Print Thread

Forum Permissions
      You cannot start new topics
      You cannot reply to topics
      HTML is disabled
      UBBCode is enabled


Thread views: 1599

Jump to

CN Forums Home


Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics