From: Gawehn, Eric [egawehn@SLAC.Stanford.EDU]
Sent: Monday, December 15, 2003 11:00 AM
To: 'Hartmut F.-W. Sadrozinski'; robert johnson
Cc: Bloom, Elliott; Gawehn, Eric; Ortiz, Eliazar; Wai, Lawrence L.; Nelson, David J.; Borden, Thomas; Tajima, Hiroyasu; Bhatnagar, B.J.; Martin, Jim; Nordby, Martin E.
Subject: Fit Check of Mylar Representations of New TKR Cable Design


The link below captures images of the Fit Check of Mylar Representations of New TKR Cable Design that was performed last Thursday (Dec. 11, 03).  More attention was focused on C-0 and C-1 due to their "cactus arm" intrusion below the +Z surface of the Grid.

Conclusion Summary:

The latest design of the TKR to TEM cables appear to fit nicely in their respective chase ways.  There appears to be sufficient cable length at the CAL to TEM interface to accommodate the required 2-Stack E-Box Shimming Operation.

This was a succsessful demonstration.  See below for additonal detail.  Please let me know if there are any issues with, or questions about, the dimensions / process identified below.

Generally what was done:

The EM SB's TKR Interface Plate was readjusted to place the +Z surface of the Grid Bay in the correct position with respect to the differences between the Mini-TKR and the latest flight design of Tray 1.  In summary, the TKR Interface Plate was lifted 0.091" from the CAL Bay section (Note: BJ's guidance was 2.6 mm [ 0.102" ].  Since we didn't have time to make special shims, I chose to use a set of washers that got us close.  I felt this was acceptable so long as we kept track of the 0.28 mm [ 0.011" ] delta).

Registration marks at the C-0 and C-1 "cactus arm" for positional alignment of the Omnetics connector to respective MCM connector interface were used to place the Mylar cable mock ups at the "mated connection" distance.

Since the cables transit around a contoured surface that is 4.6 mm in height (radially toward the Z axis) at the transition from the +Z surface of the Grid into the CAL Bay section, we made shims of that approximate height and taped them into postion for C-0 and C-1 only (i.e., bump out spacer of 4.57 mm [ 0.180" ], taped at the +Z surface to Cal Bay section transition zone). Each of Cables C-0 and C-1 went around this spacer set prior to entry into the CAL Bay section.

Registration marks at the CAL-Grid interface (i.e., -Z surface of Grid) were applied to cables C-0 through C-7 using a red Sharpie marker.  These marks were placed 67.08 mm [ 2.641" ]

from the -Z end of the mylar mock up cables.  For C-0 and C-1, Dave Nelson asked that we use the TKR to TEM connector registration circle to define placement of respective connectors at the ends of those cables.  Dave trimmed all but one of the connector's solder pins off of two connectors so that we could place the remaining registration pin of each into the corresponding hole in C-0's and C-1's registration circle (hole).

The TEM to CAL Base Plate Stand Offs were adjusted to 17.2 mm [ 0.678" ] height.  This is the nominal starting point height for the 2-Stack Electronics Box shimming operation (Note: the TEM to CAL Base Plate distance can change by +, - 0.030" depending upon the "As Built and As Inspected" dimensions for each Bay's specific set of CAL Base Plates, TEM to CAL Stand Offs, TEMs and TEM PSs).  There remains sufficient cable length to accommodate the shimming related delta height.

The Mylar cable mock ups were placed in their respective chase ways, aligned to the registration (fiducial) line at the CAL to Grid interface, and taped in place.  A black marker was used to make a dotted line that shows the outline of each cable in their chase ways.  In the photos, you will see both the dotted black out lines of the new design and be able to compare them with the pre-existing red out lines from the EM-1 Mini-TKR cable design (i.e., you can see very close correlation between the previous Mini-TKR design cable runs and the new design cable runs).

Let me know if you have any questions or suggestions,