MDM Trouble Report for 2001 Jun 29

Telescope: 1.3m
Observer(s): John Thorstensen (Dartmouth)
Instrument: Modspec + Echelle

Problem(s) Encountered:
 The telescope RA drive is acting up very badly at times.  Twice
     during the night it got stuck at some spot -- it would go east,
     but not go west.  The first time Jules came up and glared at it,
     and I backed it off and slewed past the bad spot -- Jules'
     glaring probably helped too, as the telescope dared not defy
     the Director.  The second time, I was 5 hr over in the east,
     and when I auto-slewed back to the west the telescope stuck
     at 4 hr east (and started heading for delta = -12  where I was
     going -- I stopped it at 4.5 airmasses!).  I got out of it by 
     leaning my back into the fork, hitting the slew button, and 
     literally pushing the thing past the bad spot.  The telescope
     also jumped or slipped numerous times while guiding, as it
     did a few nights ago way over in the east.  It even did this
     near the zenith. Curiously, later in the night when I was 
     working west (up to nearly 5 h) I had no problems.  The 
     temperature was also cooler by then, which may have had an 
     effect.  

     Jules and I watched the RA drive while I tried to slew past
     the bad spot -- the motors and gears all turned apparently
     normally, but the silver wheel (about 18 in diam) got stuck.
     The set and track motions were also stuck -- it wasn't just 
     slew.
~


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Submitted on 2001 Jun 29 [5:35:20]