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Hacktastic autoguider

Started by duncankitchin, 05/02/2005 05:50PM
Posted 05/02/2005 05:50PM Opening Post
I've just written up a description of my experiences so far trying to make a low-cost autoguider setup working with my Orion EQ-3 mount. The page is here:

http://www.duncankitchin.com/jump.htm?page=astrophotography/articles/autoguiding/index.htm

lots of caveats to mention - the biggest one being that I haven't actually taken any guided pictures with this yet. I'm still testing it (and hoping for a few more clear nights), but it seems to be working mostly so far (there is a list of what I'm doing on the "operation" sub-page). I thought I'd better start documenting what I've done before I get too far behind to be able to catch up.

Any comments or corrections gratefully appreciated...

Best Regards
Duncan
Posted 05/04/2005 04:50AM #1
still having some declination issues - I'm continuing to test and hopefully get to the point where I have a working setup, but there are some lingering issues that prevent me from getting that far.

The declination tracking seems to be behaving rather strangely, and I don't know quite why. It could be some flexure issues (quite possible) or maybe something in the mount.

There are a couple of issues:

there is some strange "lag" behavior in the dec axis that I don't see in the RA axis. Not a backlash issue (that's another story), but rather after a correction has been applied I see the mount start to move a couple of seconds after first application of correction, and then continue to move a couple of seconds after the correction input stops.

the second one is that the drift in declination is inconsistent. It will stay at a constant (and correctable) rate for a few minutes, and then suddenly start moving much faster, with the correction becoming ineffective. It drifts from its holding point by about 30-50 arcseconds before slowing down and gradually moving back on station.

Has anybody encountered this before? I'm kind of new to this... so I don't really know if this is expected behavior under some known set of conditions

Many thanks for any advice...

Best Regards
Duncan