MDM Trouble Report for 2006 Aug 29

Telescope: 2.4m
Observer(s): John Thorstensen (Dartmouth)
Instrument: Echelle CCD + 2in FW

Problem(s) Encountered:
Two things worth noting:

a) At the end of the night I made a move from HA = -1h 15m, 
dec = +16, to my skyflat position, which is HA = +1h 00m,
dec = +32.  The slew started out normally but very shortly
after starting, I noticed that the dome was making a loud
chattering sound (about 8 pulses per second) and it was
not moving -- i.e. the dome azimuth reading on the TCS was
not changing.  I immediately hit the stop button in the 
XTCS window, and the dome then moved to the position the
telescope happened to stop at -- that part of the dome
motion sounded normal.  I'm sorry, I didn't notice if this was
in a different direction than what it had been trying to
move before I hit stop.  I then resumed the slew and the
telescope and dome both went into position without further
problems.  I checked the position of the dome using the 
red tape markers in the dome, and it was lined up with the 
slit and agreed with the TCS dome azimuth reading -- this all
happened without the dome losing track of where it was.
The chattering I had noticed sounded like a gear slipping,
and I wonder if the track has a bad spot.

b) I had one or two hung-up sets.  Here's one that also 
happened the previous night, so it might be reproducible.
After finishing morning flatfields, I was near 1h 30m W,
dec = +32 degrees.  I commanded the telescope to go to a 
position that was at 32 degrees dec and about 1 minute east
(so it would track into the exact zenith).  The telescope
hung about 2 min of time west of the target position, and
it was a bit difficult to get it to walk into the final 
position.  

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Submitted on 2006 Aug 30 [6:23:32]