diff --git a/drill.cpp b/drill.cpp
index ffec7cc8d..b2d74cb9a 100644
--- a/drill.cpp
+++ b/drill.cpp
@@ -600,11 +600,19 @@ void ExcellonProcessor::export_ngc(const string of_dir, const boost::optional<st
     of << " )\n\n";
 
     //preamble
-    of << preamble_ext << preamble << "S" << left << target->speed
-       << "    (RPM spindle speed.)\n" << "G01 F" << target->feed * cfactor
-       << " (Feedrate)\nM3        (Spindle on clockwise.)\n"
-       << "G04 P" << target->spinup_time
-       << "\nG00 Z" << target->zsafe * cfactor << "\n\n";
+    of << preamble_ext << preamble
+       << "S" << left << target->speed << "    (RPM spindle speed.)\n\n"
+       << "G01 F" << target->feed * cfactor << " (Feedrate)\n"
+       << "G00 Z" << target->zchange * cfactor << " (Retract)\n"
+       << "T" << (*holes.begin()).first << "\n"
+       << "M5        (Spindle stop.)\n"
+       << "G04 P" << target->spindown_time << "\n"
+       << "(MSG, Change tool bit to drill size " << (bMetricOutput ? (target->tool_diameter * 25.4) : target->tool_diameter) << (bMetricOutput ? "mm" : "inch") << ")\n"
+       << "M6        (Tool change.)\n"
+       << "M0        (Temporary machine stop.)\n"
+       << "M3        (Spindle on clockwise.)\n"
+       << "G04 P" << target->spinup_time << "\n"
+       << "G00 Z" << target->zsafe * cfactor << "\n\n";
 
     tiling->header( of );
 
diff --git a/testing/gerbv_example/milldrilldiatest/expected/milldrill.ngc b/testing/gerbv_example/milldrilldiatest/expected/milldrill.ngc
index e9da6d1be..4f03ee280 100644
--- a/testing/gerbv_example/milldrilldiatest/expected/milldrill.ngc
+++ b/testing/gerbv_example/milldrilldiatest/expected/milldrill.ngc
@@ -8,7 +8,15 @@ G21       (Units == Millimeters.)
 G91.1     (Incremental arc distance mode.)
 G90       (Absolute coordinates.)
 S2000    (RPM spindle speed.)
+
 G01 F600.00000 (Feedrate)
+G00 Z10.00000 (Retract)
+T6
+M5        (Spindle stop.)
+G04 P1.00000
+(MSG, Change tool bit to drill size 1.00000mm)
+M6        (Tool change.)
+M0        (Temporary machine stop.)
 M3        (Spindle on clockwise.)
 G04 P1.00000
 G00 Z1.50000
diff --git a/testing/gerbv_example/multivibrator-basename/expected/testbase_name_milldrill.ngc b/testing/gerbv_example/multivibrator-basename/expected/testbase_name_milldrill.ngc
index df10ca2d8..1f99c27ce 100644
--- a/testing/gerbv_example/multivibrator-basename/expected/testbase_name_milldrill.ngc
+++ b/testing/gerbv_example/multivibrator-basename/expected/testbase_name_milldrill.ngc
@@ -8,7 +8,15 @@ G20       (Units == INCHES.)
 G91.1     (Incremental arc distance mode.)
 G90       (Absolute coordinates.)
 S10000    (RPM spindle speed.)
+
 G01 F100.00000 (Feedrate)
+G00 Z1.00000 (Retract)
+T1
+M5        (Spindle stop.)
+G04 P1.00000
+(MSG, Change tool bit to drill size 0.03150inch)
+M6        (Tool change.)
+M0        (Temporary machine stop.)
 M3        (Spindle on clockwise.)
 G04 P1.00000
 G00 Z0.08000
diff --git a/testing/gerbv_example/multivibrator-clockwise/expected/milldrill.ngc b/testing/gerbv_example/multivibrator-clockwise/expected/milldrill.ngc
index c50a5a568..6b42be5bc 100644
--- a/testing/gerbv_example/multivibrator-clockwise/expected/milldrill.ngc
+++ b/testing/gerbv_example/multivibrator-clockwise/expected/milldrill.ngc
@@ -8,7 +8,15 @@ G20       (Units == INCHES.)
 G91.1     (Incremental arc distance mode.)
 G90       (Absolute coordinates.)
 S10000    (RPM spindle speed.)
+
 G01 F100.00000 (Feedrate)
+G00 Z1.00000 (Retract)
+T1
+M5        (Spindle stop.)
+G04 P1.00000
+(MSG, Change tool bit to drill size 0.07087inch)
+M6        (Tool change.)
+M0        (Temporary machine stop.)
 M3        (Spindle on clockwise.)
 G04 P1.00000
 G00 Z0.08000
diff --git a/testing/gerbv_example/multivibrator-contentions/expected/milldrill.ngc b/testing/gerbv_example/multivibrator-contentions/expected/milldrill.ngc
index df10ca2d8..1f99c27ce 100644
--- a/testing/gerbv_example/multivibrator-contentions/expected/milldrill.ngc
+++ b/testing/gerbv_example/multivibrator-contentions/expected/milldrill.ngc
@@ -8,7 +8,15 @@ G20       (Units == INCHES.)
 G91.1     (Incremental arc distance mode.)
 G90       (Absolute coordinates.)
 S10000    (RPM spindle speed.)
+
 G01 F100.00000 (Feedrate)
+G00 Z1.00000 (Retract)
+T1
+M5        (Spindle stop.)
+G04 P1.00000
+(MSG, Change tool bit to drill size 0.03150inch)
+M6        (Tool change.)
+M0        (Temporary machine stop.)
 M3        (Spindle on clockwise.)
 G04 P1.00000
 G00 Z0.08000
diff --git a/testing/gerbv_example/multivibrator-extra-passes-big/expected/milldrill.ngc b/testing/gerbv_example/multivibrator-extra-passes-big/expected/milldrill.ngc
index df10ca2d8..1f99c27ce 100644
--- a/testing/gerbv_example/multivibrator-extra-passes-big/expected/milldrill.ngc
+++ b/testing/gerbv_example/multivibrator-extra-passes-big/expected/milldrill.ngc
@@ -8,7 +8,15 @@ G20       (Units == INCHES.)
 G91.1     (Incremental arc distance mode.)
 G90       (Absolute coordinates.)
 S10000    (RPM spindle speed.)
+
 G01 F100.00000 (Feedrate)
+G00 Z1.00000 (Retract)
+T1
+M5        (Spindle stop.)
+G04 P1.00000
+(MSG, Change tool bit to drill size 0.03150inch)
+M6        (Tool change.)
+M0        (Temporary machine stop.)
 M3        (Spindle on clockwise.)
 G04 P1.00000
 G00 Z0.08000
diff --git a/testing/gerbv_example/multivibrator-extra-passes-two-isolators-tiles-al/expected/milldrill.ngc b/testing/gerbv_example/multivibrator-extra-passes-two-isolators-tiles-al/expected/milldrill.ngc
index 11071afd4..b6e4be03f 100644
--- a/testing/gerbv_example/multivibrator-extra-passes-two-isolators-tiles-al/expected/milldrill.ngc
+++ b/testing/gerbv_example/multivibrator-extra-passes-two-isolators-tiles-al/expected/milldrill.ngc
@@ -8,7 +8,15 @@ G20       (Units == INCHES.)
 G91.1     (Incremental arc distance mode.)
 G90       (Absolute coordinates.)
 S10000    (RPM spindle speed.)
+
 G01 F100.00000 (Feedrate)
+G00 Z1.00000 (Retract)
+T1
+M5        (Spindle stop.)
+G04 P1.00000
+(MSG, Change tool bit to drill size 0.03150inch)
+M6        (Tool change.)
+M0        (Temporary machine stop.)
 M3        (Spindle on clockwise.)
 G04 P1.00000
 G00 Z0.08000
diff --git a/testing/gerbv_example/multivibrator-extra-passes-two-isolators-tiles/expected/milldrill.ngc b/testing/gerbv_example/multivibrator-extra-passes-two-isolators-tiles/expected/milldrill.ngc
index 6d8337575..05e04598e 100644
--- a/testing/gerbv_example/multivibrator-extra-passes-two-isolators-tiles/expected/milldrill.ngc
+++ b/testing/gerbv_example/multivibrator-extra-passes-two-isolators-tiles/expected/milldrill.ngc
@@ -8,7 +8,15 @@ G20       (Units == INCHES.)
 G91.1     (Incremental arc distance mode.)
 G90       (Absolute coordinates.)
 S10000    (RPM spindle speed.)
+
 G01 F100.00000 (Feedrate)
+G00 Z1.00000 (Retract)
+T1
+M5        (Spindle stop.)
+G04 P1.00000
+(MSG, Change tool bit to drill size 0.03150inch)
+M6        (Tool change.)
+M0        (Temporary machine stop.)
 M3        (Spindle on clockwise.)
 G04 P1.00000
 G00 Z0.08000
diff --git a/testing/gerbv_example/multivibrator-extra-passes-two-isolators/expected/milldrill.ngc b/testing/gerbv_example/multivibrator-extra-passes-two-isolators/expected/milldrill.ngc
index ea0ecf8cd..8d46db09f 100644
--- a/testing/gerbv_example/multivibrator-extra-passes-two-isolators/expected/milldrill.ngc
+++ b/testing/gerbv_example/multivibrator-extra-passes-two-isolators/expected/milldrill.ngc
@@ -8,7 +8,15 @@ G20       (Units == INCHES.)
 G91.1     (Incremental arc distance mode.)
 G90       (Absolute coordinates.)
 S10000    (RPM spindle speed.)
+
 G01 F100.00000 (Feedrate)
+G00 Z1.00000 (Retract)
+T1
+M5        (Spindle stop.)
+G04 P1.00000
+(MSG, Change tool bit to drill size 0.03150inch)
+M6        (Tool change.)
+M0        (Temporary machine stop.)
 M3        (Spindle on clockwise.)
 G04 P1.00000
 G00 Z0.08000
diff --git a/testing/gerbv_example/multivibrator-extra-passes-voronoi/expected/milldrill.ngc b/testing/gerbv_example/multivibrator-extra-passes-voronoi/expected/milldrill.ngc
index df10ca2d8..1f99c27ce 100644
--- a/testing/gerbv_example/multivibrator-extra-passes-voronoi/expected/milldrill.ngc
+++ b/testing/gerbv_example/multivibrator-extra-passes-voronoi/expected/milldrill.ngc
@@ -8,7 +8,15 @@ G20       (Units == INCHES.)
 G91.1     (Incremental arc distance mode.)
 G90       (Absolute coordinates.)
 S10000    (RPM spindle speed.)
+
 G01 F100.00000 (Feedrate)
+G00 Z1.00000 (Retract)
+T1
+M5        (Spindle stop.)
+G04 P1.00000
+(MSG, Change tool bit to drill size 0.03150inch)
+M6        (Tool change.)
+M0        (Temporary machine stop.)
 M3        (Spindle on clockwise.)
 G04 P1.00000
 G00 Z0.08000
diff --git a/testing/gerbv_example/multivibrator-extra-passes/expected/milldrill.ngc b/testing/gerbv_example/multivibrator-extra-passes/expected/milldrill.ngc
index df10ca2d8..1f99c27ce 100644
--- a/testing/gerbv_example/multivibrator-extra-passes/expected/milldrill.ngc
+++ b/testing/gerbv_example/multivibrator-extra-passes/expected/milldrill.ngc
@@ -8,7 +8,15 @@ G20       (Units == INCHES.)
 G91.1     (Incremental arc distance mode.)
 G90       (Absolute coordinates.)
 S10000    (RPM spindle speed.)
+
 G01 F100.00000 (Feedrate)
+G00 Z1.00000 (Retract)
+T1
+M5        (Spindle stop.)
+G04 P1.00000
+(MSG, Change tool bit to drill size 0.03150inch)
+M6        (Tool change.)
+M0        (Temporary machine stop.)
 M3        (Spindle on clockwise.)
 G04 P1.00000
 G00 Z0.08000
diff --git a/testing/gerbv_example/multivibrator-identical-isolators/expected/milldrill.ngc b/testing/gerbv_example/multivibrator-identical-isolators/expected/milldrill.ngc
index df10ca2d8..1f99c27ce 100644
--- a/testing/gerbv_example/multivibrator-identical-isolators/expected/milldrill.ngc
+++ b/testing/gerbv_example/multivibrator-identical-isolators/expected/milldrill.ngc
@@ -8,7 +8,15 @@ G20       (Units == INCHES.)
 G91.1     (Incremental arc distance mode.)
 G90       (Absolute coordinates.)
 S10000    (RPM spindle speed.)
+
 G01 F100.00000 (Feedrate)
+G00 Z1.00000 (Retract)
+T1
+M5        (Spindle stop.)
+G04 P1.00000
+(MSG, Change tool bit to drill size 0.03150inch)
+M6        (Tool change.)
+M0        (Temporary machine stop.)
 M3        (Spindle on clockwise.)
 G04 P1.00000
 G00 Z0.08000
diff --git a/testing/gerbv_example/multivibrator-no-tsp-2opt/expected/milldrill.ngc b/testing/gerbv_example/multivibrator-no-tsp-2opt/expected/milldrill.ngc
index fcac47005..1e07a30db 100644
--- a/testing/gerbv_example/multivibrator-no-tsp-2opt/expected/milldrill.ngc
+++ b/testing/gerbv_example/multivibrator-no-tsp-2opt/expected/milldrill.ngc
@@ -8,7 +8,15 @@ G20       (Units == INCHES.)
 G91.1     (Incremental arc distance mode.)
 G90       (Absolute coordinates.)
 S10000    (RPM spindle speed.)
+
 G01 F100.00000 (Feedrate)
+G00 Z1.00000 (Retract)
+T1
+M5        (Spindle stop.)
+G04 P1.00000
+(MSG, Change tool bit to drill size 0.03150inch)
+M6        (Tool change.)
+M0        (Temporary machine stop.)
 M3        (Spindle on clockwise.)
 G04 P1.00000
 G00 Z0.08000
diff --git a/testing/gerbv_example/multivibrator-no-zbridges/expected/milldrill.ngc b/testing/gerbv_example/multivibrator-no-zbridges/expected/milldrill.ngc
index 1aff71566..afdd93108 100644
--- a/testing/gerbv_example/multivibrator-no-zbridges/expected/milldrill.ngc
+++ b/testing/gerbv_example/multivibrator-no-zbridges/expected/milldrill.ngc
@@ -8,7 +8,15 @@ G20       (Units == INCHES.)
 G91.1     (Incremental arc distance mode.)
 G90       (Absolute coordinates.)
 S10000    (RPM spindle speed.)
+
 G01 F100.00000 (Feedrate)
+G00 Z1.00000 (Retract)
+T1
+M5        (Spindle stop.)
+G04 P1.00000
+(MSG, Change tool bit to drill size 0.03150inch)
+M6        (Tool change.)
+M0        (Temporary machine stop.)
 M3        (Spindle on clockwise.)
 G04 P1.00000
 G00 Z0.08000
diff --git a/testing/gerbv_example/multivibrator-two-isolators/expected/milldrill.ngc b/testing/gerbv_example/multivibrator-two-isolators/expected/milldrill.ngc
index df10ca2d8..1f99c27ce 100644
--- a/testing/gerbv_example/multivibrator-two-isolators/expected/milldrill.ngc
+++ b/testing/gerbv_example/multivibrator-two-isolators/expected/milldrill.ngc
@@ -8,7 +8,15 @@ G20       (Units == INCHES.)
 G91.1     (Incremental arc distance mode.)
 G90       (Absolute coordinates.)
 S10000    (RPM spindle speed.)
+
 G01 F100.00000 (Feedrate)
+G00 Z1.00000 (Retract)
+T1
+M5        (Spindle stop.)
+G04 P1.00000
+(MSG, Change tool bit to drill size 0.03150inch)
+M6        (Tool change.)
+M0        (Temporary machine stop.)
 M3        (Spindle on clockwise.)
 G04 P1.00000
 G00 Z0.08000
diff --git a/testing/gerbv_example/multivibrator/expected/milldrill.ngc b/testing/gerbv_example/multivibrator/expected/milldrill.ngc
index df10ca2d8..1f99c27ce 100644
--- a/testing/gerbv_example/multivibrator/expected/milldrill.ngc
+++ b/testing/gerbv_example/multivibrator/expected/milldrill.ngc
@@ -8,7 +8,15 @@ G20       (Units == INCHES.)
 G91.1     (Incremental arc distance mode.)
 G90       (Absolute coordinates.)
 S10000    (RPM spindle speed.)
+
 G01 F100.00000 (Feedrate)
+G00 Z1.00000 (Retract)
+T1
+M5        (Spindle stop.)
+G04 P1.00000
+(MSG, Change tool bit to drill size 0.03150inch)
+M6        (Tool change.)
+M0        (Temporary machine stop.)
 M3        (Spindle on clockwise.)
 G04 P1.00000
 G00 Z0.08000
diff --git a/testing/gerbv_example/multivibrator_no_zero_start/expected/milldrill.ngc b/testing/gerbv_example/multivibrator_no_zero_start/expected/milldrill.ngc
index 51ba4f88a..8a7772485 100644
--- a/testing/gerbv_example/multivibrator_no_zero_start/expected/milldrill.ngc
+++ b/testing/gerbv_example/multivibrator_no_zero_start/expected/milldrill.ngc
@@ -8,7 +8,15 @@ G20       (Units == INCHES.)
 G91.1     (Incremental arc distance mode.)
 G90       (Absolute coordinates.)
 S10000    (RPM spindle speed.)
+
 G01 F100.00000 (Feedrate)
+G00 Z1.00000 (Retract)
+T1
+M5        (Spindle stop.)
+G04 P1.00000
+(MSG, Change tool bit to drill size 0.03150inch)
+M6        (Tool change.)
+M0        (Temporary machine stop.)
 M3        (Spindle on clockwise.)
 G04 P1.00000
 G00 Z0.08000
diff --git a/testing/gerbv_example/multivibrator_pre_post_milling_gcode/expected/milldrill.ngc b/testing/gerbv_example/multivibrator_pre_post_milling_gcode/expected/milldrill.ngc
index c22c69ba9..66822dc02 100644
--- a/testing/gerbv_example/multivibrator_pre_post_milling_gcode/expected/milldrill.ngc
+++ b/testing/gerbv_example/multivibrator_pre_post_milling_gcode/expected/milldrill.ngc
@@ -15,7 +15,15 @@ G20       (Units == INCHES.)
 G91.1     (Incremental arc distance mode.)
 G90       (Absolute coordinates.)
 S10000    (RPM spindle speed.)
+
 G01 F100.00000 (Feedrate)
+G00 Z1.00000 (Retract)
+T1
+M5        (Spindle stop.)
+G04 P1.00000
+(MSG, Change tool bit to drill size 0.03150inch)
+M6        (Tool change.)
+M0        (Temporary machine stop.)
 M3        (Spindle on clockwise.)
 G04 P1.00000
 G00 Z0.08000
diff --git a/testing/gerbv_example/multivibrator_xy_offset/expected/milldrill.ngc b/testing/gerbv_example/multivibrator_xy_offset/expected/milldrill.ngc
index 96c67e265..6fc37dfe8 100644
--- a/testing/gerbv_example/multivibrator_xy_offset/expected/milldrill.ngc
+++ b/testing/gerbv_example/multivibrator_xy_offset/expected/milldrill.ngc
@@ -8,7 +8,15 @@ G20       (Units == INCHES.)
 G91.1     (Incremental arc distance mode.)
 G90       (Absolute coordinates.)
 S10000    (RPM spindle speed.)
+
 G01 F100.00000 (Feedrate)
+G00 Z1.00000 (Retract)
+T1
+M5        (Spindle stop.)
+G04 P1.00000
+(MSG, Change tool bit to drill size 0.03150inch)
+M6        (Tool change.)
+M0        (Temporary machine stop.)
 M3        (Spindle on clockwise.)
 G04 P1.00000
 G00 Z0.08000
diff --git a/testing/gerbv_example/multivibrator_xy_offset_zero_start/expected/milldrill.ngc b/testing/gerbv_example/multivibrator_xy_offset_zero_start/expected/milldrill.ngc
index c62074b96..bf96dec2d 100644
--- a/testing/gerbv_example/multivibrator_xy_offset_zero_start/expected/milldrill.ngc
+++ b/testing/gerbv_example/multivibrator_xy_offset_zero_start/expected/milldrill.ngc
@@ -8,7 +8,15 @@ G20       (Units == INCHES.)
 G91.1     (Incremental arc distance mode.)
 G90       (Absolute coordinates.)
 S10000    (RPM spindle speed.)
+
 G01 F100.00000 (Feedrate)
+G00 Z1.00000 (Retract)
+T1
+M5        (Spindle stop.)
+G04 P1.00000
+(MSG, Change tool bit to drill size 0.03150inch)
+M6        (Tool change.)
+M0        (Temporary machine stop.)
 M3        (Spindle on clockwise.)
 G04 P1.00000
 G00 Z0.08000
diff --git a/testing/gerbv_example/slots-milldrill-metric/expected/milldrill.ngc b/testing/gerbv_example/slots-milldrill-metric/expected/milldrill.ngc
index f27d9d1c1..3915443ce 100644
--- a/testing/gerbv_example/slots-milldrill-metric/expected/milldrill.ngc
+++ b/testing/gerbv_example/slots-milldrill-metric/expected/milldrill.ngc
@@ -8,7 +8,15 @@ G21       (Units == Millimeters.)
 G91.1     (Incremental arc distance mode.)
 G90       (Absolute coordinates.)
 S10000    (RPM spindle speed.)
+
 G01 F2540.00000 (Feedrate)
+G00 Z25.40000 (Retract)
+T1
+M5        (Spindle stop.)
+G04 P1.00000
+(MSG, Change tool bit to drill size 2.54000mm)
+M6        (Tool change.)
+M0        (Temporary machine stop.)
 M3        (Spindle on clockwise.)
 G04 P1.00000
 G00 Z2.03200
diff --git a/testing/gerbv_example/slots-milldrill/expected/milldrill.ngc b/testing/gerbv_example/slots-milldrill/expected/milldrill.ngc
index de89d8b57..d6452962b 100644
--- a/testing/gerbv_example/slots-milldrill/expected/milldrill.ngc
+++ b/testing/gerbv_example/slots-milldrill/expected/milldrill.ngc
@@ -8,7 +8,15 @@ G20       (Units == INCHES.)
 G91.1     (Incremental arc distance mode.)
 G90       (Absolute coordinates.)
 S10000    (RPM spindle speed.)
+
 G01 F100.00000 (Feedrate)
+G00 Z1.00000 (Retract)
+T1
+M5        (Spindle stop.)
+G04 P1.00000
+(MSG, Change tool bit to drill size 0.10000inch)
+M6        (Tool change.)
+M0        (Temporary machine stop.)
 M3        (Spindle on clockwise.)
 G04 P1.00000
 G00 Z0.08000
diff --git a/testing/gerbv_example/slots-with-drill-and-milldrill/expected/milldrill.ngc b/testing/gerbv_example/slots-with-drill-and-milldrill/expected/milldrill.ngc
index cafaa7c4c..5d8da1cbd 100644
--- a/testing/gerbv_example/slots-with-drill-and-milldrill/expected/milldrill.ngc
+++ b/testing/gerbv_example/slots-with-drill-and-milldrill/expected/milldrill.ngc
@@ -8,7 +8,15 @@ G20       (Units == INCHES.)
 G91.1     (Incremental arc distance mode.)
 G90       (Absolute coordinates.)
 S10000    (RPM spindle speed.)
+
 G01 F100.00000 (Feedrate)
+G00 Z1.00000 (Retract)
+T2
+M5        (Spindle stop.)
+G04 P1.00000
+(MSG, Change tool bit to drill size 0.04000inch)
+M6        (Tool change.)
+M0        (Temporary machine stop.)
 M3        (Spindle on clockwise.)
 G04 P1.00000
 G00 Z0.08000