diff --git a/Grbl/defaults/defaults_x_carve_1000mm.h b/Grbl/defaults/defaults_x_carve_1000mm.h
new file mode 100644
index 0000000..e07a23f
--- /dev/null
+++ b/Grbl/defaults/defaults_x_carve_1000mm.h
@@ -0,0 +1,69 @@
+/*
+  defaults_x_carve_1000mm.h - defaults settings configuration file
+  Part of Grbl
+
+  Copyright (c) 2012-2015 Sungeun K. Jeon
+
+  Grbl is free software: you can redistribute it and/or modify
+  it under the terms of the GNU General Public License as published by
+  the Free Software Foundation, either version 3 of the License, or
+  (at your option) any later version.
+
+  Grbl is distributed in the hope that it will be useful,
+  but WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+  GNU General Public License for more details.
+
+  You should have received a copy of the GNU General Public License
+  along with Grbl.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+/* The defaults.h file serves as a central default settings file for different machine
+   types, from DIY CNC mills to CNC conversions of off-the-shelf machines. The settings
+   here are supplied by users, so your results may vary. However, this should give you
+   a good starting point as you get to know your machine and tweak the settings for your
+   nefarious needs. */
+
+#ifndef defaults_h
+#define defaults_h
+
+  // Description: X-Carve 3D Carver CNC mill with three 200 step/rev motors driven by Synthetos
+  // grblShield at 24V.
+  #define MICROSTEPS_XY 8
+  #define STEP_REVS_XY 200
+  #define MM_PER_REV_XY (2.0*20) // 2mm belt pitch, 20 pulley teeth
+  #define MICROSTEPS_Z 2
+  #define STEP_REVS_Z 200
+  #define MM_PER_REV_Z 2.117 // ACME 3/8-12 Leadscrew
+  #define DEFAULT_X_STEPS_PER_MM (MICROSTEPS_XY*STEP_REVS_XY/MM_PER_REV_XY)
+  #define DEFAULT_Y_STEPS_PER_MM (MICROSTEPS_XY*STEP_REVS_XY/MM_PER_REV_XY)
+  #define DEFAULT_Z_STEPS_PER_MM (MICROSTEPS_Z*STEP_REVS_Z/MM_PER_REV_Z)
+  #define DEFAULT_X_MAX_RATE 8000.0 // mm/min
+  #define DEFAULT_Y_MAX_RATE 8000.0 // mm/min
+  #define DEFAULT_Z_MAX_RATE 500.0 // mm/min
+  #define DEFAULT_X_ACCELERATION (500.0*60*60) // 25*60*60 mm/min^2 = 25 mm/sec^2
+  #define DEFAULT_Y_ACCELERATION (500.0*60*60) // 25*60*60 mm/min^2 = 25 mm/sec^2
+  #define DEFAULT_Z_ACCELERATION (50.0*60*60) // 25*60*60 mm/min^2 = 25 mm/sec^2
+  #define DEFAULT_X_MAX_TRAVEL 740.0 // mm
+  #define DEFAULT_Y_MAX_TRAVEL 790.0 // mm
+  #define DEFAULT_Z_MAX_TRAVEL 100.0 // mm
+  #define DEFAULT_STEP_PULSE_MICROSECONDS 10
+  #define DEFAULT_STEPPING_INVERT_MASK 0
+  #define DEFAULT_DIRECTION_INVERT_MASK ((1<<X_AXIS)|(1<<Y_AXIS))
+  #define DEFAULT_STEPPER_IDLE_LOCK_TIME 255 // msec (0-254, 255 keeps steppers enabled)
+  #define DEFAULT_STATUS_REPORT_MASK ((BITFLAG_RT_STATUS_MACHINE_POSITION)|(BITFLAG_RT_STATUS_WORK_POSITION))
+  #define DEFAULT_JUNCTION_DEVIATION 0.02 // mm
+  #define DEFAULT_ARC_TOLERANCE 0.002 // mm
+  #define DEFAULT_REPORT_INCHES 0 // false
+  #define DEFAULT_INVERT_ST_ENABLE 0 // false
+  #define DEFAULT_INVERT_LIMIT_PINS 0 // false  
+  #define DEFAULT_SOFT_LIMIT_ENABLE 0 // false
+  #define DEFAULT_HARD_LIMIT_ENABLE 0  // false
+  #define DEFAULT_HOMING_ENABLE 0  // false
+  #define DEFAULT_HOMING_DIR_MASK 3 // move positive dir
+  #define DEFAULT_HOMING_FEED_RATE 25.0 // mm/min
+  #define DEFAULT_HOMING_SEEK_RATE 750.0 // mm/min
+  #define DEFAULT_HOMING_DEBOUNCE_DELAY 250 // msec (0-65k)
+  #define DEFAULT_HOMING_PULLOFF 1.0 // mm 
+  
+#endif
diff --git a/Grbl/defaults/defaults_x_carve_500mm.h b/Grbl/defaults/defaults_x_carve_500mm.h
new file mode 100644
index 0000000..f7d21c9
--- /dev/null
+++ b/Grbl/defaults/defaults_x_carve_500mm.h
@@ -0,0 +1,69 @@
+/*
+  defaults_x_carve_500mm.h - defaults settings configuration file
+  Part of Grbl
+
+  Copyright (c) 2012-2015 Sungeun K. Jeon
+
+  Grbl is free software: you can redistribute it and/or modify
+  it under the terms of the GNU General Public License as published by
+  the Free Software Foundation, either version 3 of the License, or
+  (at your option) any later version.
+
+  Grbl is distributed in the hope that it will be useful,
+  but WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+  GNU General Public License for more details.
+
+  You should have received a copy of the GNU General Public License
+  along with Grbl.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+/* The defaults.h file serves as a central default settings file for different machine
+   types, from DIY CNC mills to CNC conversions of off-the-shelf machines. The settings
+   here are supplied by users, so your results may vary. However, this should give you
+   a good starting point as you get to know your machine and tweak the settings for your
+   nefarious needs. */
+
+#ifndef defaults_h
+#define defaults_h
+
+  // Description: X-Carve 3D Carver CNC mill with three 200 step/rev motors driven by Synthetos
+  // grblShield at 24V.
+  #define MICROSTEPS_XY 8
+  #define STEP_REVS_XY 200
+  #define MM_PER_REV_XY (2.0*20) // 2mm belt pitch, 20 pulley teeth
+  #define MICROSTEPS_Z 2
+  #define STEP_REVS_Z 200
+  #define MM_PER_REV_Z 2.117 // ACME 3/8-12 Leadscrew
+  #define DEFAULT_X_STEPS_PER_MM (MICROSTEPS_XY*STEP_REVS_XY/MM_PER_REV_XY)
+  #define DEFAULT_Y_STEPS_PER_MM (MICROSTEPS_XY*STEP_REVS_XY/MM_PER_REV_XY)
+  #define DEFAULT_Z_STEPS_PER_MM (MICROSTEPS_Z*STEP_REVS_Z/MM_PER_REV_Z)
+  #define DEFAULT_X_MAX_RATE 8000.0 // mm/min
+  #define DEFAULT_Y_MAX_RATE 8000.0 // mm/min
+  #define DEFAULT_Z_MAX_RATE 500.0 // mm/min
+  #define DEFAULT_X_ACCELERATION (500.0*60*60) // 25*60*60 mm/min^2 = 25 mm/sec^2
+  #define DEFAULT_Y_ACCELERATION (500.0*60*60) // 25*60*60 mm/min^2 = 25 mm/sec^2
+  #define DEFAULT_Z_ACCELERATION (50.0*60*60) // 25*60*60 mm/min^2 = 25 mm/sec^2
+  #define DEFAULT_X_MAX_TRAVEL 290.0 // mm
+  #define DEFAULT_Y_MAX_TRAVEL 290.0 // mm
+  #define DEFAULT_Z_MAX_TRAVEL 100.0 // mm
+  #define DEFAULT_STEP_PULSE_MICROSECONDS 10
+  #define DEFAULT_STEPPING_INVERT_MASK 0
+  #define DEFAULT_DIRECTION_INVERT_MASK ((1<<X_AXIS)|(1<<Y_AXIS))
+  #define DEFAULT_STEPPER_IDLE_LOCK_TIME 255 // msec (0-254, 255 keeps steppers enabled)
+  #define DEFAULT_STATUS_REPORT_MASK ((BITFLAG_RT_STATUS_MACHINE_POSITION)|(BITFLAG_RT_STATUS_WORK_POSITION))
+  #define DEFAULT_JUNCTION_DEVIATION 0.02 // mm
+  #define DEFAULT_ARC_TOLERANCE 0.002 // mm
+  #define DEFAULT_REPORT_INCHES 0 // false
+  #define DEFAULT_INVERT_ST_ENABLE 0 // false
+  #define DEFAULT_INVERT_LIMIT_PINS 0 // false  
+  #define DEFAULT_SOFT_LIMIT_ENABLE 0 // false
+  #define DEFAULT_HARD_LIMIT_ENABLE 0  // false
+  #define DEFAULT_HOMING_ENABLE 0  // false
+  #define DEFAULT_HOMING_DIR_MASK 3 // move positive dir
+  #define DEFAULT_HOMING_FEED_RATE 25.0 // mm/min
+  #define DEFAULT_HOMING_SEEK_RATE 750.0 // mm/min
+  #define DEFAULT_HOMING_DEBOUNCE_DELAY 250 // msec (0-65k)
+  #define DEFAULT_HOMING_PULLOFF 1.0 // mm  
+  
+#endif
diff --git a/grbl/defaults.h b/grbl/defaults.h
index ae8c725..b72eb37 100644
--- a/grbl/defaults.h
+++ b/grbl/defaults.h
@@ -58,6 +58,18 @@
   #include "defaults/defaults_shapeoko3.h"
 #endif
 
+#ifdef DEFAULTS_X_CARVE_500MM
+  // Description: X-Carve 3D Carver CNC mill with three 200 step/rev motors driven by Synthetos
+  // grblShield at 24V.
+  #include "defaults/defaults_x_carve_500mm.h"
+#endif
+
+#ifdef DEFAULTS_X_CARVE_1000MM
+  // Description: X-Carve 3D Carver CNC mill with three 200 step/rev motors driven by Synthetos
+  // grblShield at 24V.
+  #include "defaults/defaults_x_carve_1000mm.h"
+#endif
+
 #ifdef DEFAULTS_ZEN_TOOLWORKS_7x7
   // Description: Zen Toolworks 7x7 mill with three Shinano SST43D2121 65oz-in NEMA 17 stepper motors.
   // Leadscrew is different from some ZTW kits, where most are 1.25mm/rev rather than 8.0mm/rev here.
diff --git a/grbl/defaults/defaults_generic.h b/grbl/defaults/defaults_generic.h
index 29b11a1..b5cf00b 100644
--- a/grbl/defaults/defaults_generic.h
+++ b/grbl/defaults/defaults_generic.h
@@ -45,10 +45,9 @@
   #define DEFAULT_DIRECTION_INVERT_MASK 0
   #define DEFAULT_STEPPER_IDLE_LOCK_TIME 25 // msec (0-254, 255 keeps steppers enabled)
   #define DEFAULT_STATUS_REPORT_MASK ((BITFLAG_RT_STATUS_MACHINE_POSITION)|(BITFLAG_RT_STATUS_WORK_POSITION))
-  #define DEFAULT_JUNCTION_DEVIATION 0.02 // mm
+  #define DEFAULT_JUNCTION_DEVIATION 0.01 // mm
   #define DEFAULT_ARC_TOLERANCE 0.002 // mm
   #define DEFAULT_REPORT_INCHES 0 // false
-  #define DEFAULT_AUTO_START 1 // true
   #define DEFAULT_INVERT_ST_ENABLE 0 // false
   #define DEFAULT_INVERT_LIMIT_PINS 0 // false
   #define DEFAULT_SOFT_LIMIT_ENABLE 0 // false
diff --git a/grbl/defaults/defaults_oxcnc.h b/grbl/defaults/defaults_oxcnc.h
index 4e7d56f..1c89ab8 100644
--- a/grbl/defaults/defaults_oxcnc.h
+++ b/grbl/defaults/defaults_oxcnc.h
@@ -49,7 +49,6 @@
   #define DEFAULT_JUNCTION_DEVIATION 0.02 // mm
   #define DEFAULT_ARC_TOLERANCE 0.002 // mm
   #define DEFAULT_REPORT_INCHES 0 // false
-  #define DEFAULT_AUTO_START 1 // true
   #define DEFAULT_INVERT_ST_ENABLE 0 // false
   #define DEFAULT_INVERT_LIMIT_PINS 0 // false
   #define DEFAULT_SOFT_LIMIT_ENABLE 0 // false
diff --git a/grbl/defaults/defaults_shapeoko.h b/grbl/defaults/defaults_shapeoko.h
index aaa9834..46346ea 100644
--- a/grbl/defaults/defaults_shapeoko.h
+++ b/grbl/defaults/defaults_shapeoko.h
@@ -53,10 +53,9 @@
   #define DEFAULT_DIRECTION_INVERT_MASK ((1<<Y_AXIS)|(1<<Z_AXIS))  
   #define DEFAULT_STEPPER_IDLE_LOCK_TIME 255 // msec (0-254, 255 keeps steppers enabled)
   #define DEFAULT_STATUS_REPORT_MASK ((BITFLAG_RT_STATUS_MACHINE_POSITION)|(BITFLAG_RT_STATUS_WORK_POSITION))
-  #define DEFAULT_JUNCTION_DEVIATION 0.05 // mm
+  #define DEFAULT_JUNCTION_DEVIATION 0.02 // mm
   #define DEFAULT_ARC_TOLERANCE 0.002 // mm
   #define DEFAULT_REPORT_INCHES 0 // false
-  #define DEFAULT_AUTO_START 1 // true
   #define DEFAULT_INVERT_ST_ENABLE 0 // false
   #define DEFAULT_INVERT_LIMIT_PINS 0 // false  
   #define DEFAULT_SOFT_LIMIT_ENABLE 0 // false
diff --git a/grbl/defaults/defaults_shapeoko2.h b/grbl/defaults/defaults_shapeoko2.h
index 00bd9b7..24f62e4 100644
--- a/grbl/defaults/defaults_shapeoko2.h
+++ b/grbl/defaults/defaults_shapeoko2.h
@@ -52,10 +52,9 @@
   #define DEFAULT_DIRECTION_INVERT_MASK ((1<<X_AXIS)|(1<<Z_AXIS))
   #define DEFAULT_STEPPER_IDLE_LOCK_TIME 255 // msec (0-254, 255 keeps steppers enabled)
   #define DEFAULT_STATUS_REPORT_MASK ((BITFLAG_RT_STATUS_MACHINE_POSITION)|(BITFLAG_RT_STATUS_WORK_POSITION))
-  #define DEFAULT_JUNCTION_DEVIATION 0.05 // mm
+  #define DEFAULT_JUNCTION_DEVIATION 0.02 // mm
   #define DEFAULT_ARC_TOLERANCE 0.002 // mm
   #define DEFAULT_REPORT_INCHES 0 // false
-  #define DEFAULT_AUTO_START 1 // true
   #define DEFAULT_INVERT_ST_ENABLE 0 // false
   #define DEFAULT_INVERT_LIMIT_PINS 0 // false  
   #define DEFAULT_SOFT_LIMIT_ENABLE 0 // false
diff --git a/grbl/defaults/defaults_sherline.h b/grbl/defaults/defaults_sherline.h
index 6dc9d99..8cabaec 100644
--- a/grbl/defaults/defaults_sherline.h
+++ b/grbl/defaults/defaults_sherline.h
@@ -49,10 +49,9 @@
   #define DEFAULT_DIRECTION_INVERT_MASK ((1<<Y_AXIS)|(1<<Z_AXIS))  
   #define DEFAULT_STEPPER_IDLE_LOCK_TIME 25 // msec (0-254, 255 keeps steppers enabled)
   #define DEFAULT_STATUS_REPORT_MASK ((BITFLAG_RT_STATUS_MACHINE_POSITION)|(BITFLAG_RT_STATUS_WORK_POSITION))
-  #define DEFAULT_JUNCTION_DEVIATION 0.02 // mm
+  #define DEFAULT_JUNCTION_DEVIATION 0.01 // mm
   #define DEFAULT_ARC_TOLERANCE 0.002 // mm
   #define DEFAULT_REPORT_INCHES 0 // true
-  #define DEFAULT_AUTO_START 1 // true
   #define DEFAULT_INVERT_ST_ENABLE 0 // false
   #define DEFAULT_INVERT_LIMIT_PINS 0 // false
   #define DEFAULT_SOFT_LIMIT_ENABLE 0 // false
diff --git a/grbl/defaults/defaults_simulator.h b/grbl/defaults/defaults_simulator.h
index 1ffe1cf..0843722 100644
--- a/grbl/defaults/defaults_simulator.h
+++ b/grbl/defaults/defaults_simulator.h
@@ -46,10 +46,9 @@
   #define DEFAULT_DIRECTION_INVERT_MASK 0
   #define DEFAULT_STEPPER_IDLE_LOCK_TIME 25 // msec (0-254, 255 keeps steppers enabled)
   #define DEFAULT_STATUS_REPORT_MASK ((BITFLAG_RT_STATUS_MACHINE_POSITION)|(BITFLAG_RT_STATUS_WORK_POSITION))
-  #define DEFAULT_JUNCTION_DEVIATION 0.02 // mm
+  #define DEFAULT_JUNCTION_DEVIATION 0.01 // mm
   #define DEFAULT_ARC_TOLERANCE 0.002 // mm
   #define DEFAULT_REPORT_INCHES 0 // false
-  #define DEFAULT_AUTO_START 1 // true
   #define DEFAULT_INVERT_ST_ENABLE 0 // false
   #define DEFAULT_INVERT_LIMIT_PINS 0 // false
   #define DEFAULT_SOFT_LIMIT_ENABLE 0 // false
diff --git a/grbl/defaults/defaults_zen_toolworks_7x7.h b/grbl/defaults/defaults_zen_toolworks_7x7.h
index a6e8787..44fa02a 100644
--- a/grbl/defaults/defaults_zen_toolworks_7x7.h
+++ b/grbl/defaults/defaults_zen_toolworks_7x7.h
@@ -53,7 +53,6 @@
   #define DEFAULT_JUNCTION_DEVIATION 0.02 // mm
   #define DEFAULT_ARC_TOLERANCE 0.002 // mm
   #define DEFAULT_REPORT_INCHES 0 // false
-  #define DEFAULT_AUTO_START 1 // true
   #define DEFAULT_INVERT_ST_ENABLE 0 // false
   #define DEFAULT_INVERT_LIMIT_PINS 0 // false  
   #define DEFAULT_SOFT_LIMIT_ENABLE 0 // false