1. Tracker Subsystem GLAST LAT Project 1 ANNEX 1 to NCR/FM/INFN/PI/372 STATIC TEST TORQUE LOSS OUT OF SPEC’S ON BOTTOM TRAY S/N 005 Andrea Tenze andrea.tenze@pi.infn.it MRB meeting - 17 February 2005

2. Tracker Subsystem GLAST LAT Project 2 Contents Introduction References Test work flow, hardware and interfaces Test results Corrective action

3. Tracker Subsystem GLAST LAT Project 3 Introduction Description of non conformance –Corner Flexure -X+Y nut torque loss after first direction test (X) exceeds 2.3Nm limit Input to discussion –Brief description of test performed with highlight to the interface hardware –Resume of results obtained with BT Static Tests

4. Tracker Subsystem GLAST LAT Project 4 Procedure: –LAT-PS-03993-03 –LAT-PS-04245-01 Test result: –LAT-TD-04758  BT S/N 001 –LAT-TD-04759  BT S/N 002 –LAT-TD-05440  BT S/N 003 –LAT-TD-05493  BT S/N 006 –LAT-TD-05774  BT S/N 005 –LAT-TD-05775  BT S/N 007 –LAT-TD-05776  BT S/N 008 References

5. Tracker Subsystem GLAST LAT Project 5 Test work flow Bottom Tray mounting Grid installation Distance between bottom side of flexure and bottom side of grid measurement 1 st axis test Nut torque loss measurement Distance between bottom side of flexure and bottom side of grid measurement 2 nd axis test Nut torque loss measurement Distance between bottom side of flexure and bottom side of grid measurement Pre test Bottom Tray CMM measurement Post test Bottom Tray CMM measurement Note: 1)Already prescribed in procedure not prescribed in procedure 2)Torque loss measurement method (not specified in procedure): with torque meter, unscrewing Acquisition of displacement and load data Post Processing of data, obtaining Load vs Displacement curves Acquisition of displacement and load data Comparison with pre test measurement Check of curve closure

6. Tracker Subsystem GLAST LAT Project 6 Test hardware interfaces Steel grid simulation plate LAT-DS-03509 –No floating nut present Shoulder stud –DS-02791 but considered non flight hardware –With Dycronite patch and without locking feature on both sides threads –At their first usage (for BT005) Nut –DS-03925 –At their first usage (for BT005) Cones –DS-02787 and DS-02788 –At their fifth usage (for BT005) Hex bushings –DS-02789 –At their fifth usage (for BT005)

7. Tracker Subsystem GLAST LAT Project 7 Notation Test direction and notation

8. Tracker Subsystem GLAST LAT Project 8 Test results Torque loss (Nm) –procedure limit 2,3Nm +X side-X side+Y side-Y side BT S/N Test axis CF +X +Y CF -X -Y CF +X -Y CF -X +Y SF +X +y SF +X -y SF -X +y SF -X -y SF +Y +x SF +Y-x SF -Y +x SF -Y -x 005 X 1,861,981,962,751,161,211,091,290,941,801,051,22 Y 1,030,851,962,021,271,351,471,460,651,070,790,91 007 X 1,901,881,582,920,840,970,991,281,491,331,251,58 Y 1,091,340,921,941,021,061,010,930,750,840,721,04 008 X 1,961,911,902,821,040,981,110,832,282,051,291,91 Y 1,221,230,941,871,721,061,150,950,911,410,931,40 Note –Value of torque loss is greater than required limit only on first direction test and on the same location –Respect to all the CF, CF –X+Y is the only one which does not have aligned inner and outer cones (see LAT-PS-04245)

9. Tracker Subsystem GLAST LAT Project 9 Test results Displacement vs load curves –All curves obtained show closure in X direction and in Y direction X direction plots (double click in the picture to see all DZ probes plots)

10. Tracker Subsystem GLAST LAT Project 10 Test results Y direction plots (double click in the picture to see all DZ probes plots)

11. Tracker Subsystem GLAST LAT Project 11 Test results Displacement range obtained at zero load (dead band width) –Range has been obtained by means of sum of maximum and minimum displacement obtained between - 50N + 50N during the test –Data obtained for BT005, BT007 and BT008 are comparable to data obtained with previous BT tested X DIRECTION TEST – dead band widthY DIRECTION TEST – dead band width BT S/ND1ZD2ZD3ZD1LAD2LAnoteBT S/ND1ZD2ZD3ZD1LAD2LAnote [mm] 0010,1300,1330,1200,1490,1182nd axis0010,1000,0940,1200,1190,0971st axis 0020,1120,1220,1060,2150,2242nd axis0020,1300,0820,1190,1780,1541st axis 0030,1150,1050,0990,1780,1821st axis0030,1450,1190,1600,1450,1302nd axis 0060,1270,1370,1130,1640,1531st axis0060,1820,1240,1980,1680,1812nd axis 0050,1220,1050,0710,1790,1891st axis0050,0920,0870,1200,1510,1162nd axis 0070,1050,1110,0930,1350,1341st axis0070,1170,1060,1040,1500,1192nd axis 0080,0790,0770,0710,1490,1581st axis0080,1000,0690,0830,1630,1152nd axis Pre and post test measurement on BT005 –(measure pre test) - (measure post test) < 0.15 mm at all flexure hole axis

12. Tracker Subsystem GLAST LAT Project 12 Corrective action Proposed corrective action –Procedure variation Modification of Pass/Fail criteria for Bottom Tray –Elimination of actual torque loss limit –Introduction of: »pre and post test measurement comparison »zero load dead band width limit (for this kind of analysis a discussion has already been implemented) Introduction of measurement in step by step procedure –Nut torque loss will be an information obtained from test but no more considered as pass/fail criteria for Bottom Tray Proposal for BT005 –Use as is Comments –Any decision will have an influence on NCR filed for already tested Bottom Tray NCR FM/INFN/PI/378 - Bottom Tray S/N 007 NCR FM/INFN/PI/382 - Bottom Tray S/N 008