LBT Q3 2007 Engineering LBT Q3 2007 Engineering ReviewReview

MCSC Mount Control SystemMCSC Mount Control System

26-Oct-200726-Oct-2007 LBT Q3 2007 Engineering RevieLBT Q3 2007 Engineering Revieww

Highlights (Q3/2007)Highlights (Q3/2007)

Identified source of azimuth encoder Identified source of azimuth encoder signal nulls signal nulls

Azimuth encoder declared Azimuth encoder declared salvageablesalvageable

Elevation motor brushes inspected Elevation motor brushes inspected and one replaced due to heat and one replaced due to heat damagedamage

26-Oct-200726-Oct-2007 LBT Q3 2007 Engineering RevieLBT Q3 2007 Engineering Revieww

Open IssuesOpen Issues

TechnicalTechnical Occasional unexplained elevation tracking errorsOccasional unexplained elevation tracking errors ELFR motor winding damage from Q1/07. Brush failure suspected.ELFR motor winding damage from Q1/07. Brush failure suspected. Low azimuth and elevation accelerationLow azimuth and elevation acceleration Unexplained phase discrepancy between azimuth and elevation Unexplained phase discrepancy between azimuth and elevation

encoder signalsencoder signals Elevation brake capacity appears to be diminished to less than 206 Elevation brake capacity appears to be diminished to less than 206

kN*mkN*m ScheduleSchedule

NoneNone FinancialFinancial

Postponed ordering spare azimuth encoder tape on financial grounds Postponed ordering spare azimuth encoder tape on financial grounds ResourceResource

MCS competing for resources mainly against rotator development MCS competing for resources mainly against rotator development efforteffort

Azimuth encoder progress in Q4/07 is contingent on progress made on Azimuth encoder progress in Q4/07 is contingent on progress made on issue #772.issue #772.

26-Oct-200726-Oct-2007 LBT Q3 2007 Engineering RevieLBT Q3 2007 Engineering Revieww

Progress (Q3/2007)Progress (Q3/2007)

Planning From Q2 ReviewPlanning From Q2 Review Elevation and azimuth motor brush inspected Elevation and azimuth motor brush inspected

and if necessary replaced and if necessary replaced √√ Order replacement azimuth encoder tape – Order replacement azimuth encoder tape –

postponed Q1/08postponed Q1/08 Azimuth encoder tests planned for Q4/07 – on Azimuth encoder tests planned for Q4/07 – on

scheduledscheduled Tape installation expected in Q4/07 – canceledTape installation expected in Q4/07 – canceled

Additional ProgressAdditional Progress Damaged tape salvageableDamaged tape salvageable Identified source of azimuth encoder tape Identified source of azimuth encoder tape

signal nullssignal nulls

26-Oct-200726-Oct-2007 LBT Q3 2007 Engineering RevieLBT Q3 2007 Engineering Revieww

Planning (Q4/2007)Planning (Q4/2007)

Install azimuth main encoder read Install azimuth main encoder read headsheads

Commission azimuth encoderCommission azimuth encoder Inspect/repair elevation brakesInspect/repair elevation brakes Order azimuth encoder tape Q1/08Order azimuth encoder tape Q1/08