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LBT Q4 2007 Engineering Review. Primary Mirror Cells. Highlights (Q4/2007). Cells still behaving well Y-axis of SX speed decrease identified and corrected PIC replaced in SX HP-5 4 Actuator failures this Fall ?!?. Open Issues. Technical Cell Documentation deficient and/or nonexistent
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LBT Q4 2007 Engineering Review Primary Mirror Cells
Highlights (Q4/2007) • Cells still behaving well • Y-axis of SX speed decrease identified and corrected • PIC replaced in SX HP-5 • 4 Actuator failures this Fall ?!? LBT Q4 2007 Engineering Review
Open Issues • Technical • Cell Documentation deficient and/or nonexistent • Hardpoints have lower stiffness that desired, meet 80N/m (min required) • Air boxes hot, require insulation/ventilation • Actuator test stand undocumented/not maintainable • Dew-point of cell compressed air not being monitored • Presence of high concentrations of chlorine through mirror cells point to mirror cleaning solutions as the probable source/cause of corrosion products removed from the cells and air ejector. • Schedule • None • Financial • ETS Test Stand proposal will be cost-plus, >$140k • Resource • Mountain staff limitations pace work at Observatory • ETS staff limitations pace cell documentation effort LBT Q4 2007 Engineering Review
Progress (Q4/2007) • SX HP-5 PIC replaced • SX oscillation identified and corrected • SX breakaway limits readjusted LBT Q4 2007 Engineering Review
Planning (Q4/2007) • Dew-point monitors will be ordered/installed. • ETS to modify hardpoint monitor board (TBD) • ETS will rework Actuator Calibration Stand (TBD) • Engineering will complete DX characterization measurements 2nd qtr LBT Q4 2007 Engineering Review