ANNEX 1 to NCR/FM/INFN/PI/372 STATIC TEST TORQUE LOSS OUT OF SPEC’S ON BOTTOM TRAY S/N 005

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

2. Contents • Introduction • References • Test work flow, hardware and interfaces • Test results • Corrective action

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. References • 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

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

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. Notation • Test direction and notation

8. Test results • Torque loss (Nm) • procedure limit 2,3Nm • 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. Test results • X direction plots (double click in the picture to see all DZ probes plots) • Displacement vs load curves • All curves obtained show closure in X direction and in Y direction

10. Test results • Y direction plots (double click in the picture to see all DZ probes plots)

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 • Pre and post test measurement on BT005 • (measure pre test) - (measure post test) < 0.15 mm at all flexure hole axis

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