Guiding slipping - Why?

[bazza]

I'm imaging using a 10" LX200 OTA onto which is piggybacked a William Optics Zenthstar EDII 80mm APO for guiding - all mounted on a Losmandy G11. Camera is a Starlight Xpress SXVF-H9 and guide head (Using Maxim).

Last night, I started imaging NGC 7635 - it was almost at the zenith - guiding was spot on with no trailing at all in the images (240 sec subs).

As the night wore on, ( & NGC 7635 started to move Westward, I noticed the guiding started to slip - slight trailing started to appear - guide corrections were increasing. By the end of the night, I just couldn't get it to guide as it had been at the start of the night.

I gave in to tiredness!

Do you think it's the balance that's out - or something else?

(Incidentally, I was using 4 sec exposures for guiding).

Grateful for all advice received.

Barry Morton

Worcester - UK.

[blinky]

Yep sounds o me like the balance but remember...I am no expert!

[daz]

Could be the fact it was at the meridian and should've had a meridian flip?

Also, no expert.....

[Beyond_Vision]

Could be the fact it was at the meridian and should've had a meridian flip?

Also, no expert.....

I dont think fork mounts do a Meridian flip Daz. It may be the dec clutch slipping when near the zenith. My LX90 10" suffered from this problem so I got the Peterson Clutch Kit.

Regards

Kevin

[ngc2403]

hey,

I don't know about dec motor/clutch slipping or balance problems but if your polar alignment was off then the telescope would start to trail worse and worse the further from the meridian it got.

also there maybe flecture and a slow drift but if it just got worse the longer it went on then it is probably polar alignment.

ally