gEDA-user: Part Rotation in XY-data

["John Luciani" <jluciani@xxxxxxxxx>]

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@xxxxxxxxxxxxxx
http://www.seul.org/cgi-bin/mailman/listinfo/geda-user