We have a few nights of totally cloudy nights ahead, so I've decided to check some stuff out. Firstly, I have noticed recently that my guiding shows that in both RA and DEC the guide pulses flip backwards and forwards across the zero line trying to keep the star aligned. To me that showed some loosness in my worm gears. I did a quick check and found:
* On the DEC axis I had not tightened up the saddle itself properly when I did the replacement of the bearings recently (It had to be removed temporarily to do the bearing replacement). A few gentle tweaks on the grub screws and now can't feel any loosness/backlash.
* On the RA axis it turned out that I hadn't tightened up the worm gear float adjusters enough. I'd read that you had to leave them loose, but obviously not that loose.
Despite not having the above sorted, I was achieving 0.55 to 0.7 arc secs RMS guiding, however the graphs just didn't look right (too many corrections; particularly in RA).
My next task will be aligning my secondary properly as, looking at my images, it looks quite likely that I have an issue there. See stars in this image:
M51
What are you guys doing during cloudy nights?
* On the DEC axis I had not tightened up the saddle itself properly when I did the replacement of the bearings recently (It had to be removed temporarily to do the bearing replacement). A few gentle tweaks on the grub screws and now can't feel any loosness/backlash.
* On the RA axis it turned out that I hadn't tightened up the worm gear float adjusters enough. I'd read that you had to leave them loose, but obviously not that loose.
Despite not having the above sorted, I was achieving 0.55 to 0.7 arc secs RMS guiding, however the graphs just didn't look right (too many corrections; particularly in RA).
My next task will be aligning my secondary properly as, looking at my images, it looks quite likely that I have an issue there. See stars in this image:
M51
What are you guys doing during cloudy nights?
