LASER INTERFEROMETER GRAVITATIONAL WAVE OBSERVATORY LIGO Laboratory / LIGO Scientific Collaboration LIGO LIGO-D0900528-v1 April 1, 2009 InVacuum Cable Assembly Details R Abbott, C Osthelder Distribution of this document: LIGO Scientific Collaboration This is an internal working note of the LIGO Laboratory California Institute of Technology LIGO Project – MS 18-34 1200 E California Blvd Pasadena, CA 91125 Phone (626) 395-2129 Fax (626) 304-9834 E-mail: info@ligo.caltech.edu Massachusetts Institute of Technology LIGO Project – NW22-295 185 Albany St Cambridge, MA 02139 Phone (617) 253-4824 Fax (617) 253-7014 E-mail: info@ligo.mit.edu LIGO Hanford Observatory P.O Box 1970 Mail Stop S9-02 Richland WA 99352 Phone 509-372-8106 Fax 509-372-8137 LIGO Livingston Observatory P.O Box 940 Livingston, LA 70754 Phone 225-686-3100 Fax 225-686-7189 http://www.ligo.caltech.edu/ LIGO LIGO-D0900528-v1 Table of Contents Tools Required and Recommended – Band-It – DMC AFM8 Crimper – Shield Jig – Tubing Cutter – Materials, Parts and Suppliers – Current In-Vacuum Assemblies – Assembly Procedures – Index – Photo and Drawing Index – LIGO LIGO-D0900528-v1 Tools Required and Recommended One of the most important tools used in making the shielded and sheathed cable assemblies for LIGO is the Band-It The Band-It is distributed by the Glenair Inc and it makes the termination of shielding and outer sheaths incredibly easy The Band-It cinches a double loop of stainless steel strapping around the materials to be joined concentrically Because the pressure is applied very evenly around the joint, it is nearly impossible to distort or crush the inner tube used as the termination point If removal of the band is required, it is a simple matter of cutting the buckle of the band off with a wire cutter The Band-It tool part number 600-058 is used with a 240” wide band The buckle width is 350” The standard length, flat strap is part number 600-052 Pre-coiled bands are available, but there seems no advantage to using them and they take up far more storage space The Band-It tool part number 600-061 is used with a 120” wide band This band has a 195” buckle and the standard flat unit is part number 600-057 This band is very useful for the smallest cable assemblies or those with stringent mass limitations Information regarding these products, including instructional videos, is available online at: http://www.glenair.com/banding/ For sales and other requests, contact Glenair Inc via telephone at 818-247-6000, fax at 818-5009912 or email at sales@glenair.com The Band-It model 600-058 and stainless steel bands, part number 600-052 LIGO LIGO-D0900528-v1 A special crimping tool is a must when attaching fine wire to the tiny pins and sockets of connectors used in the vacuum system The DMC model AFM8 is a precision crimping tool with four compressing jaws to apply an even force on the part to be crimped The AFM8 comes with an eight-position depth selector for proper pin location relative to the crimping jaws The DMC AFM8 and custom depth stop made from 18 gauge wire Through experimentation, it was found that the AFM8 could easily accommodate the pins used in the SRI Micro-D connector with the addition of a 400” depth stop Made from scrap 18 gauge wire, the stop is inserted into the crimper before placing the pin into the tool Information about the line of crimpers available from DMC can be found at: http://www.dmctools.com/Catalog/miniature_adjustable_crimp_tools.htm DMC can be contacted directly by telephone at 407-855-6161, fax at 407-855-6884 or email at dmc@dmctools.com LIGO LIGO-D0900528-v1 A length of narrow tubing is used to place wire inside the copper shielding to create a cable A piece of copper braid is spread open and slid over the tubing and the fine teflon-insulated wires are inserted into the tube In order to prevent distortion of the braid, reducing the effective shielding, great care must be taken when handling the braid A bullet-shaped piece of material should be machined to fit over an end of the tubing used to gently expand and open the braid This end cap ensures that the braid pattern remains intact and relatively free of distortions These two parts make a simple shield jig Custom PEEK end cap fits into end of 9/32” O.D aluminum tube to protect the copper braid The end cap shown above was fashioned from a piece of PEEK rod The rod was chucked into a drill press and shaped with a hand file and sandpaper by Ben Abbott It fits snugly into a length of 9/32” O.D (.014” wall) aluminum tubing and is flush with the outside diameter Also shown in the above photo is a good quality tubing cutter These are available from any plumbing supply or hardware store It is used for making the small tubing inserts needed when terminating the shield at a point isolated from a connector After cutting the tube, be sure to remove burrs and smooth rough edges to avoid damaging the wire that will pass through the tube Aside from the usual hand tools found in the lab, a set of thread taps and a tap wrench are required when constructing certain cable assemblies Useful tap sizes are #4-40, #6-32, #8-32, and LIGO LIGO-D0900528-v1 possibly #10-32 Kits are available with standard taps and corresponding drill bits, simplifying the selection process Materials, Parts and Suppliers 50% Copper Shield Braid 125” braid – customer P/N 24x3x40BC (refer to PO #75-5031912) 250” braid – customer P/N 24x4x40 (refer to PO #75-5033433) Continental Cordage Corp 75 Burton St Box 623 Cazenovia NY 13035 Phone 315-655-9800 Fax 315-655-9686 PEEK Braid 5/32” Mono PEEK sleeving - P/N 6759 E.L Wood Braiding Co., Inc 542 Rt 11, South PO Box 753 Marathon NY 13803 Phone 607-849-9663 Fax 607-849-3035 Email elwoodbraiding@stny.rr.com http://elwoodbraiding.com/ FEP Teflon Insulated Wire 28AWG – P/N CZ1105-1F 29AWG – P/N CZ1104-1F Kapton Insulated Wire 28AWG – P/N CW6951 Cooner Wire Co., Inc 9265 Owensmouth Ave Chatsworth CA 91311 LIGO LIGO-D0900528-v1 Cooner Wire contact information cont Phone 818-882-8311 Fax 818-709-8281 Email direct from website http://www.coonerwire.com/home.html Aluminum Tubing (all 12” length and 014” wall thickness, sold in packages of three) 3/16” – P/N TTRA-05-12-03 7/32” – P/N TTRA-06-12-03 ¼” – P/N TTRA-08-12-03 9/32” – P/N TTRA-09-12-03 Copper Tubing (all 12” length and 014” wall thickness, sold in packages of three) 1/8” – P/N TTRC-03-12-03 5/32” – P/N TTRC-04-12-03 Copper Sheet 021” thick, 12” square sheet – P/N SMC-021-D Small Parts Inc Phone 800-220-4242 http://www.smallparts.com/ ... AFM8 Crimper – Shield Jig – Tubing Cutter – Materials, Parts and Suppliers – Current In-Vacuum Assemblies – Assembly Procedures – Index – Photo and Drawing Index – LIGO LIGO-D0900528-v1 Tools... Required and Recommended One of the most important tools used in making the shielded and sheathed cable assemblies for LIGO is the Band-It The Band-It is distributed by the Glenair Inc and it makes... buckle and the standard flat unit is part number 600-057 This band is very useful for the smallest cable assemblies or those with stringent mass limitations Information regarding these products,