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.
12/2/2004
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.
13/2/2004
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.