MDM Trouble Report for 2017 Sep 22

Telescope: 2.4m
Observer(s): Weil (Dartmouth)
Instrument: OSMOS/B

Problem(s) Encountered:
At the beginning of the night a short load screeching noise 
could be heard in the control room for about 5-10 seconds
every 5-10 minutes. Went out the dome and could not seem to
locate the problem. I thought it might have had to do with the
dome not rotating totally cleaning. 

In the middle of the night the noise got worse, becoming almost
constant. At this point it was clear that that something in the
telescope or dome were grinding against each other. I walked into 
the dome to see if I could find the origin of the noise and it
appeared to be coming from the telescope mount near the
RA/DEC encoders. When standing next to the RA/DEC encoder it sound like
a high pitch grinding noise.

Throughout the night as the noise got worse, tracking was lost
in the guider. For one exposure the guide star
got completely lost that was not recoverable during a long exposure.

I did not want to damage anything on the telescope so I closed 
the telescope at 2am. 

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Submitted on 2017 Sep 23 [3:22:49]