Unbalanced moments in az arm
mar10
The moments in the azimuth arm come from:
- dome weight: 210000 lbs
- ch: 35000 lbs
- radial center of mass (about 430 feet)
- counterWeight: 45000 lbs, distance 145 feet.
- Dome zaOffset from optic axis za to center of mass za : -1.9
degrees.
- Dome motion 1.06 to 19.69 degrees za (optic axis)
- ch motion : 0 to 20 degrees za
The plots show the unbalanced moments
in the azimuth arm (.ps) (.pdf)
for various configurations.
- Top: dome moves 1.06 degrees to 19.69 degrees in za:
- ch at 8.83 degrees za (stow). This is the current setup we use.
- ch at 20 degrees za.
- ch tracks dome
za when dome above za=10.
- Bottom: ch moves 0 to 20 degrees in za, dome remains fixed.
- dome at 8.83 degrees za (stow). This is the current setup we
use.
- dome at 13.5 degrees
za.
- dome at 15.0 degrees
za.
- dome at 19.69 degrees
za.
- The dashed horizontal lines show +/- 12000 kip-feet.
Notes:
- tracking with the ch when dome above 10 degrees za only saves
3000 kip feet when dome is at 19.69 deg. The resulting unbalance is
still larger than the allowed 12000 kipfeet unbalance.
processing:x101/100308/unbtorques.pro
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