Date: Sat, 08 May 1999 12:56:02 -0500
From: Bill Boroski
Subject: Re: 2.5m obslog 990507 ( MJD 51306 ) - 15deg stop
Bob, Jeff, and Ellyne,
Before we bypass these interlocks, it would be good to take a look at the
15-degree stop actuator to see if there is anything obvious causing the
piston not to retract.  The fact that Dan heard the air actuate when he
expected it to suggests that the interlock logic is working properly, so
this sounds like a mechanical problem.  Perhaps there's dirt or crud
causing the piston shaft or the wedge block to stick, or perhaps there's a
problem with air pressure.
I'd appreciate if you would  take a look at this in the daylight to see if
you can identify what's going on.  Perhaps one person near the actuator as
another moves the telescope in altitude past the actuation point.  Please
keep me posted on what you learn.
Thanks,
-Bill
At 07:54 AM 5/8/99 -0600, Dan Long wrote:
>
>                           FRIDAY MAY 7, 1999
>
>                     APACHE POINT OBSERVATORY SDSS 2.5m
>
>                              OBSERVING  LOG
>
>
>   At the end of the night while I was putting the telescope away, the 15
>degree stop did not retract as the telescope came down in elevation, even
>though the telescope was in stow in azimuth.  In fact I heard the air
>actuate at the time it should have retracted, but it just didn't move.  I
>went back up and came back down again, but it still didn't move.  I then
>helped the cylinder along pulling it back by hand.  It stayed retracted
>once I moved it out of the way.  If it is still acting up tomorrow, I would
>recommend disconnecting the air to it and bypassing the interlocks
>associated with it, so the telescope will operate without complaining that
>it isn't in the proper state.
>
>
>                                     Dan
>
>
>
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>