Date: Mon, 01 Mar 1999 09:18:48 -0600
From: Bill Boroski
Subject: Re: 2.5m obslog 990227
Hi Dan,
Wanted to reply to your comment regarding windbaffle/telescope motion when
the 15-deg stop is not in.   The interlocks are designed to prohibit
windbaffle azimuth motion unless the 15-deg stop is in.  Motion is disabled
by dropping power to the windbaffle az drive motors.  Purpose of this
interlock is to prevent the windbaffle/telescope assembly from driving
azimuthally into the platform rail.  The 15-deg stop comes in automatically
when the telescope altitude reaches approx 18 deg, at which elevation the
windbaffle safely clears the railing.
The telecope is free to move within the windbaffle in response to requests
to be able to do engineering work on the telescope drives while the
telescope is inside the enclosure.  The telescope is constrained in the
windbaffle so it can't go too far, yet it can move far enough for low speed
tracking tests.
Hope this helps.
-Bill
At 05:17 AM 2/28/99 -0700, you wrote:
>
>                        SATURDAY FEBRUARY 27, 1999
>
>                     APACHE POINT OBSERVATORY SDSS 2.5m
>
>                              OBSERVING  LOG
>
>
>   The telescope was opened at about 17:00 today.  The engineering camera
>was mounted, and the telescope balanced.  The counterweight settings are
>around 275 for the engineering camera on the new rotator.  The "wrap-less"
>connection scheme for the latches and engineering camera worked well
>enough.
>
>   As this was the first time back on the sky since the major winter
>shutdown, there were a few wrinkles to be ironed out.  The air to the Az
>brake and the 15 degree stop were not connected.  One interesting note;
>the windscreen will not move in azimuth if the 15 degree stop isn't
>physically in place, though the telescope will to the extent it can.
>
>   Later the altitude stopped responding.  It took me a while to find it
>was the old cart-not-in-the-doghouse trick which was stymieing motion.  The
>cart had moved just enough to let up on the switch.  While trying to find
>the problem, I discovered that the altitude was significantly out of
>balance front to back as one approached zenith.  This I think can be
>attributed to the new rotator motor being larger and more toward the front
>of the PSS than the old one.  Fortunately moving the remaining
>counterweight cover from the front of the PSS to the back got the balance
>very close.
>
>   Inspite of the first time back on the sky gremlins, we had a fairly
>productive night.  The mirror systems behaved, and we got a decent start on
>primary collimation.   Current primary settings are
>
>setmir   0   -31.3   -19.6   -1069   1708
>galil   6660  -1912  -2146  14475  -41584  -41584
>
>
>                                Dan
>
>
>