diff --git a/site_ansto/instrument/bilby/config/motors/motor_configuration.tcl b/site_ansto/instrument/bilby/config/motors/motor_configuration.tcl
index c922acef..7e6e43b5 100644
--- a/site_ansto/instrument/bilby/config/motors/motor_configuration.tcl
+++ b/site_ansto/instrument/bilby/config/motors/motor_configuration.tcl
@@ -22,6 +22,11 @@ sicslist setatt att_pos klass instrument
 make_gap_motors ss1hg gap ss1ho offset ss1r ss1l mm first/horizontal
 make_gap_motors ss1vg gap ss1vo offset ss1u ss1d mm first/vertical
 
+# Sample aperture positions
+# D2.5 is at 0 and D40 is at 333
+sapmot positions 333 288 248 213 179 146 114 84 55 27 0
+make_coll_motor_1 sap sap sapmot count
+
 ## Time of flight calculation
 # Length of a guide
 ::utility::mkVar lenguide float user lenguide true instrument true true