Mechanical Meeting 10 February, 2004.
Martin Nordby(MN), Mike Menning(MM), Alessandro Brez, Riccardo Bagagli, Emilio Rapposelli, Nanda K. Menon.
General discussion about the INFN concerns about the coordination and the need to work together. Martin gave the details of the SLAC org setup.
MM handed INF the list from Jeff Tice that showed the material status. This is the list of the materials that need to be shipped to INFN from SLAC. Mirco Bagni (MB) has been designated by INFN to be Jeff's counterpart here in Italy. MB is responsible for maintaining the data base of the parts and document. The data base issue was explained by Sandro. The data base will be a complete system with various components that deal with different aspects of the final design of the tower. It was agreed that SLAC and INFN will come to an agreement as to what data has priority in terms of Tower integration onto the GRID at SLAC. This data will be given priority to be uploaded into the database if there is any scheduling aspects. Giovanni Foglia(GF) will be the person at PLYFORM
MM requested some clarification about the production scheduling and how somebody will be aware of an impending deviation of the production process. INFN has explained their process to control this and a short synopsis of the overall integration of a Tower.
The tour of the clean room was conducted and it was very useful for MM and MN. Lot of their doubts were satisfied. Then we had the lunch break.
Started reviewing the design drawing for the Tower assembly, Bottom Tray assembly and Mid Tray assembly Tooling as the hard ware is not available here in Pisa. MN has a better understanding of how/why to transfer the Tower alignment knowledge from Pisa to SLAC. The flexure design and tolerances were discussed. MN has action to talk to Hytek about the dimensioning of the Flexure.
There was some discussion about the need to transfer the Tower alignment information from INFN to SLAC. The discussion was centered on correlating the Tower info to alignment balls here in Pisa on a CMM and then transforming that information to the grid reference frame and re-shooting the alignment balls after installation on the flight GRID.
The bottom tray fabrication is in discussion with respect to the FLEXURE tolerances.
The current plan per MN is to wire EDM the conical holes in the corner FLEXURE after the FLEXURE assembly is complete. There may need to be some coating of the SS cones which is the outer cone so that there is no galling and the fit is good. The schedule for the delivery of the FLEXURE is in discussion. the FLEXURE will be delivered to Pisa 10 weeks after the drawing is released. It will take 2 weeks for the first bottom tray to be manufactured. This will be used for the vibration test of the EM tower. The second bottom tray will be used for the Tower A.
The schedule for the complete EM Tower after verification of the alignment will be end of first week of June. The introduction of the EM Tower vibration has only impacted the delivery of the Tower A by about 1 week. The Tower A will be finished and ready for environmental tests second week of July. This is almost completely being driven by the delivery of the FLEXURES.
The EM tower vibration will be completed the mid week of June.
The grounding of the bottom tray was explained by INFN to MN. There is an issue in that the back side of the GND pad on the MCM may actually be touching the C/C instead of the Ti part of the tray and so another solution is necessary. INFN is thinking of curing a cell of the bottom tray core with a wire inserted into the cell and then connect the wire to the corner FLEXURE solid metal part via a M2 screw hole. MN was requested to insert this hole in the design. MN had a question about where the MCM will be pushed for the gluing process. Sandro said that it will have to be determined and documented in real time. INFN further requested MN to have a tighter tolerance for 2 of the holes on the bottom tray structural closeout. the size of these holes will be different for the 2 different closeouts.
The conclusion from yesterday and today are the FLEXURE hole (conical) should be referenced very strongly to the reference holes on the side of the corner brackets. It is further agreed that the attachment to the GRID will be with 3 concentric cones and 9 eccentric cone washers. However the EM vibration may have to be done with all eccentric cones. The side FLEXURE drawing is needed by INFN to complete the tooling drawing due to the change of the thickness. INFN action to define in a sketch of the desired shipping container and the Tower lifting device and, red line version of the thermal strap for better assembly.
The drawing review for the tolerances were completed for the Bottom tray close out and the corner FLEXUREs. The conclusion for the corner FLEXURE was to fit the 2 pieces and then match drill the holes.
The shims for the FLEXURE to GRID interface was discussed and two possibilities were discussed for the procurement of these - either SLAC do the drawing and INFN buy the shims or SLAC design the shim and do bulk procurement and ship a defined number to INFN. The shims are required for all 12 location of the interface. The methods for the installation of the shims was discussed. SLAC is going to investigate to see if the Tower/GRID interface can be made Metric. This would facilitate the manufacture of the non flight integration hardware to be manufactured in Italy. The shim shape was discussed and agreed to. The shims to be used here in Italy will have tabs to ease the installation. The number and types of shims was discussed (~6000 & 2 or 3 types). Shim design for INFN will have a tab for ease of installation. the shims, cones and nut will be changed out in SLAC when the Tower is delivered.
The side FLEXURE tolerances were discussed. SLAC presented the difference of the side FLEXURES and the required orientation of the bottom tray due to this. SLAC has given a copy of the Tracker IDD to INFN. The narrow FLEXURES go on the +x and +y face of the bottom tray. INFN explained how the coordinate system of the top and mid trays are assigned and how this is used for the Tower assembly. Discussion about the possibility to assemble the Tower with the wrong orientation of the trays. The side FLEXURE discussions are finished.
The corners that is to be used for the alignment are +x+y,+x-y & -x-y.