Re: RA spikes towards west
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Hi Magnus,
Given all that you have done, I doubt it is the mount drive.... but other ideas follow....
The camera optics are very sensitive to any mechanical looseness.??
When I've gotten glitches in my autoguider camera tracking, I often traced it to a slight wiggle in some one of the 1.25 inch tube or lockdown screws.? I doubt it really is the drive itself.? Last night I found a wiggle in a 90 degree?angle prism diagonal.??
My main deep sky cameras have 2 inch round nosepieces, but even those can loosen up.?
Tiny thumbscrews ...?? I often replace tiny thumbscrews with larger 6-32 or maybe 8-32 pointed end setscrews. ( I think I did that with some Oldham couplers too. I could not get the tiny Allen head wrench to really grab the tiny setscrew.? ?It pays to have a tap and die set, drill and number drill assortment around!)
Hope you solve your glitch trouble,
Michael
On Tue, Aug 4, 2020, 3:52 AM Magnus Larsson < magnus@...> wrote: Hi!
I seem to have run into a problem where I think I'd need some smart
input. I've cleaned and relubed my G11, put everything together and
adjusted the RA worm as usual. Now I am also running a somewhat heavier
side-by-side setup. Carefully balanced in 3 directions. I have an OPW
(new design) with a high precision worm. Non-tucked motors. There is a
belville washer in the OPW.
What I get is spikes in the west direction, if I read it correctly. See
the last 3 guiding sessions in the attached PHD2 logfile, or the
attached screenshot of one of them. There are a few spikes in the other
direction as well.
Now, I'm surprised that these are in the west direction. My thinking is
that if there were something in the way, if the worm was not clean, or
if there was a problem with bearings or something else, these would
cause friction and spikes in the east, not the west, direction.
I've been playing with:
- adjusting worm against ring gear, so I can easily rotate it but not
more play than that
- adjusting the tightness of the clutches - thinking this was sticktion.
But it seems this far not to make a difference. Loosening or tightening
- no perceptible change.
- cables etc - I can not see anything that would cause problems, and
again, is this not in the wrong direction for that?
And I should mention that I was imaging M27, relatively high in the sky,
and it was no perceptible wind at all.
So: I think I have experimented with "the usual" suspects of bad guiding
behavior on the G11, and need some help thinking about what else this
could be. Should I dismantle it all again, clean and relube? Or what
could cause this kind of behavior? What am I missing here?
Magnus
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Michael Herman