Bruce I guide at 400 or 800mm with my st4, I also get long strings of 0's and
1's. You really need to determine if you have st4 or g11 problems, and the way
to do this is to attempt some manual guiding...increase the power to 400x and
keep that star bisected on the wire for at least 4 minutes..did it have a smooth
gradual drift in RA or did it have sudden jumps that were difficult to correct
quickly enough?
An st4 is much less capable than you are, so if you cant manually guide then the
st4 will not be able to do it either. The st4 has a steep learning curve.
Find out what your problem is first, before you attempt a fix. Let me know if
you need help with the st4 or g11.
midniterider@... wrote:
Hello Members:
Like Chris Woodruff, I too may have a problem with RA, but this is
a G11 on a permanent pier/observatory setting. The pier is 6"
schedule 40 pipe with gusseting, etc. with a concrete footing 30" in
diameter and 36" deep...I know it's not moving.
Using an ST4 through 500mm (1/2 meter) guidescope, notable others
claim long strings of 0's and 1's for errror. Using the same setup,
I
get values of 2's and 3's with occasional 4's. Extending the FL with
a 2X Barlow to get the recommended 1-meter guiding focal length, the
G11 can't even keep the star in the box, which results in the alarm
going off.
I've taken the mount apart 5 times now, cleaned all the bearings
and relubed...found no seized bearings. I've adjusted the worm to
gear "mesh" from loose to tight and tight to loose, swapped RA and
DEC
worms, bearing blocks, and motors to no avail.
Even though I have a permanent setup, every time I take the head
off to do this maintenance, I have to Dec drift align after
re-mounting. I do this at 312X and even though the star will remain
bissected on the Dec reticle line for 15 minutes (meridian and
eastern
horizon), I've noticed that the star will drift back and forth across
the RA line. This appears to be "slop" between the worm and gear,
but
I don't want to have all the play removed and create binding because
I
know this will eventually damage the gear/worm.
Like Chris, I'm limited to about 30 second unguided CCD images
and
only about half won't be trailed. With the ST4 on the guidescope
(1/2
meter) and the imaging CCD on the main OTA, the images are OK if the
ST4 doesn't display an error over 2. Of course, that will only
happen for exposures less than a minute.
The pier is filled with fine dry sand and is solid. All bolts,
mounting hardware, and guidescope rings, focuser locks, etc. are
tight. I have no problem calibrating the ST4 and getting it to
guide.
What in the world am I doing wrong? I apologize for the long post.
Regards,
Bruce Inscoe
Herm
Astropics
