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 stages.
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 rotation angle: