West Mirror Cover Fail-to-Open

Thursday, December 1, 2016 10:09 AM

Problem(s) Encountered:

After taking a break to let the clouds clear somewhat, we attempted to start up again. When we did, the West mirror cover petal did not open, though we could hear it trying. We slewed as far as we could to the W and a bit N to see if we could open it by gravity, which didn''t work, so we used the rope to pull it open. It opened far more gently than it usually does, and when we attempted to slew over to a new target, it immediately closed itself again.

We went back to zenith, closed all the mirror covers, left them alone for 30 minutes while another cloud went over, and then tried to re-open again.The west mirror cover petal still will not open, so we''re calling it a night.


Needle valve adjustments have been performed.  More work will be needed to fine-tune the system, but it is at least working again.  One thing to note is that if a problem occurs where the west petal is stuck on the baffle, the telescope should be slewed east, not west.  This allows gravity to shift the baffle slightly, freeing up the petal.