Minutes of the Tracker Meeting
May 13, 2004
Action
Items:
-
Dave:
discuss with Jack whether a carbon filter is enough in the bakeout vacuum
chamber.
-
Mike:
send correct vibe fixture drawing out for release
-
Arthur:
send the updated cone installation and alignment plan to Italy
-
Jeff:
procure Aeroglaze 9929 primer
-
Riccardo:
send redlines of tray-panel drawings to SLAC for as-built condition, as
discussed in Pisa
-
Sandro:
send redlines of tray-assembly (G&A) drawings to SLAC to conform to the
actual procedure
Aluminum: Jeff has 7075-T73 bars arriving from LA
tomorrow. ½” bar is kind of large. Martin is looking into other materials. He wants Emilio to check on availability in
Italy. He will send Email to Emilio on
what materials to look for, including titanium. Ben said that titanium
may require an anti-gall coating. Paul
Baird noted that GSFC can get titanium rod for cones in 4 days.
Emilio
reported that the bakeout procedure will be ready on Saturday. He said that a cold trap is not possible but
the pump has a carbon filter to prevent oil from entering the chamber. Dave will discuss with Jack Goodman whether
this is an issue for such a vacuum chamber (not high vacuum).
Mike
reported on the lifting fixture design.
Not all insert locations are available because of the cables. John Ku did some stress analysis and thought
it was okay, but Emilio wanted more margin for handling stresses. Mike is now developing an alternate concept.
Mike
also reported on the cable holder design.
He wants the cable to go halfway and loop back. Some concern was expressed about bending the
cables, so Mike will do an experiment.
He recommends using connector savers.
Vibe
fixture drawings were sent to Natalie yesterday for approval. Mike forgot to remove “check print” from the
drawings, so he will fix that.
Mike
expressed an urgent need for INFN to write a procedure for installation of a
tower or bottom tray onto a fixture, using the cones. Arthur nearly has an update for the assembly plan draft, which he
will send soon to Italy.
Arthur
is working on tool design. The highest
priority tool is the cone extraction tool.
The second priority tool is a spanner wrench. Another 2 tools are for setting alignment---less priority.
Chris
asked about the status of software for alignment. Dave said that he met this week with Tom Borden. The AI&T tower simulator will be used
alignment trailblazing. All necessary
features can be put into that simulator.
Robert Ruland’s team will use it for development of software and
procedures. The test is scheduled for the
first week of June.
There
was some discussion of using the EM tower for practicing the alignment
procedure in Italy.
Cable
clips: John is doing the stress analysis now.
They are made of aluminum and will be installed onto a completed tower. Custom nests are used for tooling
balls. The nests stay there during
vibration but are removed before the ACD is mounted. The assembly sequence is to prebend the cable and install. Then put on sidewalls. Then turn the tower right side up and slip the
bracket under the cable.
Cable
bending tools: Arthur is working on the S bending tool for cactus arms: it will
be procured this week. He has a concept
for the bending tool used at the Grid interface. Nothing has been done yet on the top tray bend. Arthur will do it.
Pisa
needs to check out the EM-2 EGSE using the newly released procedure. Robert will send the documents to Luca. Dave Nelson and Hiro are working on a
breakout board to allow currents to be measured.
In
a discussion of primers for the black paint it became evident that we need an
NCR written. The 9924 primer has been used
instead of the 9929 called out on the drawings. Jeff needs to procure the 9929 primer immediately. The 9924 is suitable for aluminum but is not
ideal for carbon composites. Test at
Pisa indicated a need to use primer on the carbon-carbon. The paint peels without primer. With the 9924 primer it does not peel. Jeff will ask the manufacturer about
experience with 9924 on graphite, as opposed to carbon composite.
Flex
cables: Martin reported that they are updating the flight drawings now
following his redlines. Final check
prints may be available as early as tomorrow.
He expects to start the release cycle middle of next week. First we need a final check against
electrical layouts.
Sidewall
prepreg material will ship next week to Plyform. Plyform may have to start their job in parallel with COI testing,
due to a long time lag in the testing. Nanda
requested that we get Ben involved with COI to get an early indication of
success in the testing.
Jeff
is ordering nuts for the vibration test.
The static test can use standard stainless nuts with a lubricant. There was a discussion about contamination
and it was resolved that we just have to clean the flight tray after testing,
in case some lubricant gets onto the flexure.
Jeff
reported that the static-test Grid simulator will arrive the 17th or
18th, then will be CMM’ed at SLAC.
There is no coating on the first one.
The second one will have a black anodized surface.