MDM Trouble Report for 2005 Nov 12

Telescope: 2.4m
Observer(s): DePoy el al (OSU)
Instrument: CCDS + Retrocam

Problem(s) Encountered:
The RA motor drive stalled several times at least once every 5 minutes between 10:35 UT and 12:44 UT. It may be periodic with the spur gear, and/or dependant on telescope position. It was 9 degrees Celsius (warmer than many nights in the past month), so it’s probably not a temperature problem. When it stalled, the friction from the worm gear on the spur gear made a very pure, high-toned chirp, so it may be caused by an excessive preload on the worm gear.

For the first 30 minutes while telescope was pointed at TR-1 (RA 06 07 35 DEC +24 05 40), it was not a problem, but at 10:35 UT it began. At 10:45, we moved to US708 (RA 09 33 20 DEC + 44 17 06) and it continued. At 12:44 UT (still at US708), it stopped. We also mysteriously lost the guide star once last night at roughly the same time, and probably while viewing US708.

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Submitted on 2005 Nov 13 [6:34:05]
NOTE: This trouble report replaces the previous report for 2005 Nov 12