[Bubba Gateley, Jeff Kissel, Calum Torrie, Krishna Venkateswara, Eddie Sanchez, Rich Savage, Timesh Mistry]
This is a delay post from last week.
Rick and I went down to EX end station with a tape measure to see how much room there was to physically do the drilling. All the photos ca be found in the DCC G1901341 entry. The key photos will be attached here.
We notice that we have ~11 inches from the vacuum chamber to the HEPI pier however, there is less space than expected as there is a vacuum flange protruding from the vacuum chamber (first image - DSC_1492.JPG). Also, there is only 4.5 inches of space on the top surface of the BSC pier as a result of the vacuum flange (second image - DSC_1487.JPG). Moreover, the top surface is not as the CAD drawing depict. Instead of a flush plate with gussets in the corners, there is a square place raised up and welded (third image - DSC_1500.JPG). In addition, there are 2 extra steel plates on the sides of the BSC pier that are untreated (not painted) that are not present in the CAD drawings this extra room is required in the NCAL mount to accommodate for this (fourth image - DSC_1482.JPG) this, increasing the thickness of the side wall that we have to drill though. The weld due to the side plates will interfere with the current proposed positions for the NCAL mount (fifth image - DSC_1498.JPG and sixth image - DSC_1478.JPG).
We have also found that the 90 degree angled drill we inteded to use will not be suitable for this job as it is a snug fit to get the drill into the space, without any drill bits in it. We will order a lower profile drill that will be capable of drilling into the mild steel pier.
I have attached imaged of the drill bushings, the new drill and the how space available at EX at LHO as a results of the new drill.
The first two images (DSC_1529.jpg and DSC_1530.jpg) show the dimension of the drill head.
The third and fourth images (DSC_1538.jpg and DSC_1539.jpg) show the clearance around the BSC pier
The fifth image (DSC_1543.jpg) shows how close one can get to the chamber flange.
The sixth image (DSC_1545.jpg) has the parts that have been ordered (Drill, drill bushings, captive screws and the drill bits).
The seventh image (DSC_1525.jpg) has the full length measurement of the drill.
Consulting with Bubba, the process of drilling into the BSC pier should now be possible. We are awaiting on a final design of the jig that will help locate precisely locate the holes and ensure straight holes. The other challenge will be not breaking any taps due to the thickness of the BSC pier (especially on the sides).
[Laurance Datrier, Dripta Bhattacharjee, Timesh Mistry]
We went to the X end to take some more pictures of the BSC ISI pier. They are attached to this comment. We have the side view of the pier, measuring the span of the pier from the chamber. This should also give better measurement of the hole in the pier.
