23 June 2004:
The waveplate mechanism has been fully reassembled and rewired. To the
right is an view of the entire mechanism with the pneumatically controlled
sliding plates, sans optics.
The photo on the left shows the detail of the cable wrap and wire harness
connections. Below are closeups of the quarter- and half-waveplate rotation
Below are movies of the waveplate insert and remove maneuvers:
08 June 2004:
Mike has begun the reassembly of the waveplate mechanism. All the parts are
back from anodization. Below are pictures of the mechanism with all the
mechanical, but not electronic, components assembled. The ring on top of the
mechanism is the interface ring for the kinematic mount with the invar
collimator tube, which is part of the structure. Below the mechanism is
the field lens/guider mount. The final picture shows the cable wrap and
details of the light-weighting performed on the mechanism body.
24 February 2004:
The waveplate rotation mechanism was fully tested. The "waveplate" (the actual
optics are not in place) was rotated in a sequence of 8 positions and the
detent removed before and inserted after each move. This sequence was then
repeated several times. There was effectively zero exposure time; i.e. the
next move started immediately after the preceding one. A MPEG movie
(3Mb) at left shows the test.
10 February 2004:
The waveplate mechanism has been fully wired and testing has been performed.
The pneumatic slides work well and we are testing the waveplate rotation
software and encoder. Below left is the mechanism, partly disassembled (I was
lax getting pictures of the fully assembled mechanism). Below right is a
closeup of the quarter-waveplate encoder and rotation motor installed.
The waveplates themselves have not yet been inserted.
26 September 2003:
Fabrication and assembly of the waveplate mechanism has begun. Below are some
photos of the mechanism as it now stands. There are two sliding plates, one
over the other, for the waveplates and waveplate blanks.
Closeups of the waveplate mounting areas:
Closeup of pneumatic detent area for precision placement of waveplate