Progress Report of Region3
General: Click on image to enlarge to higher resolution
1) Frame related
a) Delivery:
David Armstrong Spoke with "Mo" at Atlas Fibre yesterday. They hope to ship the frames July 23, but will
certainly, guaranteed, ship them by July 27th. They will make sure they
are cleaned nicely before shipping, not like the "scrap"
parts they sent us earlier.
b) Scraps:
The scrap parts arrived 2 week ago. We received 4 long
G-10 boards (92.5" x 6.0" x 0.520") and 3 short G-10 boards
(33.0" x 6.0 x 0.520"). All scraps boards have been sandblasted to a thickness of 0.520" +-0.002".
Graduate student John Leckey and Klaus drove down to JLab and measured
the flatness of the boards on a huge granite table located in the JLab
machine shop. We used a 36" long precision straight edge that has been
verified to be flat better than 0.1mil by placing the straight
edge on the granite table, illuminate the edge with a flash light and
check for "light gaps" (couldn't find any). Then we placed the
G-10 boards on the granite table and checked both sides with the
straight edge and a set of gauge feelers. All boards were flat within
the tolerances of +-2mil. Surprisingly the shorter boards have more
gaps than the long boards. The short boards showed a rise in thickness
at the last ~2inches towards the ends.
However the boards were really dusty due to the sandblasting which is not what you want in a clean room.
2) Glue Jig Design
Has been sent out last week to "Vision Machine and Fabrication
Corp." located in Hampton and will be finished within 4 weeks ($3150).
We are using standard cast aluminum tooling plates with a flatness and
parallelism tolerance of +-5um.
Here are the technical drawing page: http://dilbert.physics.wm.edu/qweak/drawings/JigBoards/GlueJig/
Mockery: It has been and it will be always a struggle to get some
professional support from JLab when W&M does not have a
chargeable JLab account ... For instance, forget about shopping in the
JLab stockroom when you are a W&M postdoc. All we got for
free was a recommendation for the above company from the JLab
machine shop. No QA/QC or essential consulting/guidedance because this
would be a chargeable service ...
3) Infrastructure
We received the aluminum profiles 2 weeks ago in order to build
a bridge over the laser table. Last week the wire scanner has been
mounted
on the crossbar were it can be moved along the grooves to various scan
position (you need at least 3). Currently the wire scanner is scanning
a section of ~50 strung wires.
The wire scanner did not work properly after we ran it with a home made
15' long extension cord. The wire scanner could not find it's home
position, the position readout was not stable.
It turned out that it was caused by cross talk between the position
readout wires and a sense wire of the stepper motor that stopped the
motor erratically. After adding a 2nd extension cable solely for the
stepper motor cables everything worked again.
Current Setup in lab: http://dilbert.physics.wm.edu/elog/Construction/441
b) Delay Line Multiplexer
We were promised to get a prototype Mux board tomorrow in our
next biweekly electronics meeting ?! The delay line project is
practically completed. Time to order some crates and send out the board
design to manufactures.
4) Wire Tension Measurement
Graduate student Siyuan Yang started on the wire
tension measurement project. We are currently setting up a simple
test setup where a wire will be strung with a known weight (tension) and
soldered under tension to copper cladded PCBs. Currently we are using a stack of small 3/4" x 3/4" x 1/4" thick Neodymium block magnets (3170 Gauss surface field).
Methode used: A function generator (FG) is hooked up to the wire crossing
partially a magnetic field. The function generator sends an AC
current (sinus) through the wire. A CCD camera is used to track the
resulting vibration/deflection of the wire. Tune the FG frequency to the
resonance frequency of the tensioned wire.
A snapshot is here: http://dilbert.physics.wm.edu/elog/Software/267
A photo of the setup: http://dilbert.physics.wm.edu/elog/Software/268
5) Rotator
The $90k item has arrived on 06-26-2007 at JLab. See: http://dilbert.physics.wm.edu/elog/Construction/436 . Has not rotated yet ...
That's all folks,
|{laus