(1) DOCUMENT CHANGE NOTICE (DCN): DCN No. E00900174-v1 (2) INFORMATION: DOCUMENT No. TITLE * D0900773-v2: Pier Table * D0900657-v2: Optical Lever Pier Weldment Prototype * E0900145-v2: Drawing Tree - Optical Lever Pier Weldment Prototype (3) CHANGE DESCRIPTION (FROM / TO): D0900773-v2: Pier Table RIGHTMOST VIEW: * Added Note "MACHINE FACE 125 MICROINCH ROUGHNESS" * Dim .62 +.00/-.05 was .50 MIN * Added parallelism .005 * Flatness .001 was .003 D0900657-v2: Optical Lever Pier Weldment Prototype RIGHTMOST VIEW: * Eliminated reqiurement - Parallelism .010 of Table faces * Dim 65.00 +.26/-.05 was 65.00 +/-.05 NOTE 6 IS- WELD ITEM 3 TO ITEMS 1 WITH FLATTEST SIDE OF ITEM 3 FACING UPWARD IN VIEW. WAS- WELD FLATTEST SIDE OF ITEM 3 TO ITEMS 1. NOTE 7 IS- AFTER COMPLETION OF THE WELDMENT, MACHINE AT TOP OF ITEM 3 TO NOTED SPECIFICATIONS IF NECESSARY. LEVEL THE UPPER FACE OF ITEM 3 (SQUARE WITH MACHINING HEAD) BEFORE MACHINING. WAS- AFTER COMPLETION OF THE WELDMENT, MACHINE AT TOP OF ITEM 3 TO NOTED SPECIFICATIONS. E0900145-v2 Drawing Tree - Optical Lever Pier Weldment Prototype * Updated revision levels of drawing numbers D0900657 & D0900773, to v2. (4) REASON FOR CHANGE: In the weldment D0900657, post-weld .010" parallelesim of the table D0900773 upper & lower faces is very difficult to inspect. Instead, it will be expected that this parallelism will change less than any post-weld change to the flatness of the upper face, which will be post-weld inspected and re-machined if necessary. If re-machined, the table surface must be squared with the machine head to optimize final parallelism with its lower face. To avoid warpage, the pre-weld table thickness will be increased. The welding will be done carefuly with heat extraction methods to minimize warpage. (5) SIGNATURES REQUESTED: Michael Smith (6) DCN DISTRIBUTION: Michael Smith (7) NOTES: