Michael, Krishna
We made a lot of progress on the BRSX upgrades today.
The new belt driven turntable was installed which is designed to have less vibrations during damping. The previous turntable used gears and a loud stepper motor which caused vibrations which in turn drove up modes of the balance. (see 26265) The new turntable uses a belt and a much quieter Bekchoff stepper motor which has noticably less vibrations. Also, the Mightex camera, a 2048 pixel CCD read over USB, was replaced with a Basler camera which has 4096 pixels and is read over ethernet. This new camera will remove the USB communication error which was causing the system to crash every couple weeks.
Additionally, we replaced the laptop and NI DAQ card with a Beckhoff computer and electronics. Both the C# code, which turns images into angles, and the PLC code, which controls the damper and sends data out, are working and data is being sent out to the seismic front ends. However, the EPICS communication has yet to be set up so many of the diagnostic channels are not being read.
The balance is rung up to a very large amplitude due to the work today but we've begun to slowly damp it down with the new turntable.
Here are some pictures of the damper before and after the upgrade. The first one shows the old turn table in the bottom left under the arm and the Mightex camera wrapped in foil on the very top of the autocollimator. The second one show the old stepper motor and gears. The third shows the new turn table on the left, the new electronics box in front of the chamber, and the new Basler camera and mount on the top. The third is more detailed view of the turntable with the new stepper motor in the back and the drive belt running below the damping masses.
Also attached is a video showing the smooth motion of the damper. This was while the balance was rung up so the damper is moving from the counter-clockwise limit in beginning of the video to almost the clockwise limit about two thirds through.