I have an SMD XTAL, rectangular package, pad in each corner. When I place two footprints on the top side of the board I get angle=0 and side=top for both parts in the xy-data file (which is correct). If I move one part to the bottom without rotation the part on the bottom has an angle=90 in the xy-data file. If I rotate a part on the top side the angle appears to be negative for counter-clockwise rotation.
I do not know what most assembly houses require. I took a quick look at IPC-2581 "Generic Requirements for Printed Board Assembly" (March 2004, pages 11-12). The convention in IPC-2581 states both parts should have angle=0 and the part on the bottom should have a mirror attribute. Angles are positive for counter-clockwise rotation. Was the xy-data done for a specific machine or specification? xy-data is below. (* jcl *) # 0deg rotation, X11 top, X21 bottom X11,"XTAL__FOX_FQ5032B-Series.fp","(unknown)",950.00,4182.00,0,top X21,"XTAL__FOX_FQ5032B-Series.fp","(unknown)",550.00,4182.00,90,bottom # 90deg ccw, X12 top, X22 bottom X12,"XTAL__FOX_FQ5032B-Series.fp","(unknown)",950.00,3957.00,270,top X22,"XTAL__FOX_FQ5032B-Series.fp","(unknown)",550.00,3982.00,180,bottom # 180deg ccw, X13 top, X23 bottom X13,"XTAL__FOX_FQ5032B-Series.fp","(unknown)",950.00,3682.00,180,top X23,"XTAL__FOX_FQ5032B-Series.fp","(unknown)",550.00,3632.00,270,bottom # 270deg ccw, x14 top, x24 bottom X14,"XTAL__FOX_FQ5032B-Series.fp","(unknown)",950.00,3457.00,90,top X24,"XTAL__FOX_FQ5032B-Series.fp","(unknown)",550.00,3407.00,0,bottom -- http://www.luciani.org _______________________________________________ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user