There are 8 Gregorian motors numbered uphill
to downhill: 11,12,21,22,31,32,41,42 They are located at:
Aux mode allows you to disable 1 motor and continue
The hydraulic brake slows the dome when it moves downhill.
07dec08 motor torques during
Project a2130 (galfacts) scans the telescope
along the meridian at .0234 degs/sec moving from za=2 to 20 (about).
They do this continuously for 6 hours at a time. Data from
06,07,08dec08 was used to look at the Gregorian torques during this
Each panel shows 2 motors. Black,green is moving uphill,
red/blue is moving downhill
The speed is abs(.0234) deg/sec
When moving downhill the torque goes to 0 between 10 and 15
deg za then it begins to rise again.
We only measure the absolute value of the torque.
When the down torque goes through 0, it is changing the
direction from the motors pushing uphill (gt 15deg) to the
motors pushing down hill (against the hydraulic brake).
Top: motors 11,12
2nd: motors 21,22
3rd: motors 31,32
4th: motors 41,42
The torque histogram versus velocity looks different for mot31
moving downhill. It is working harder than the others. This only
shows up in the bins with fewer counts (when the velocity was
changing) so it may not be real.
Moving uphill the slope of tq vs za is different for the each
motor pair. The downhill motor of each pair is working harder at
Moving downhill the motors have to start pushing downhill
between 10-15 deg za.
The uphill motor of each pairs starts to push downhill
sooner than the downhill motor.