toolhead: Specify maximum acceleration and velocity in toolhead class

Change the config file so the maximum accel and velocity are specified
in the "printer" section instead of the individual "stepper" sections.
The underlying code limits the velocity and accel of the toolhead
relative to the print object, so it makes sense to configure the
system that was as well.

Signed-off-by: Kevin O'Connor <kevin@koconnor.net>

config/example.cfg

@@ -26,10 +26,6 @@ enable_pin: !ar25
 #   Enable pin (default is enable high; use ! to indicate enable low)
 step_distance: .0225
 #   Distance in mm that each step causes the axis to travel
-max_velocity: 500
-#   Maximum velocity (in mm/s) of the stepper
-max_accel: 3000
-#   Maximum acceleration (in mm/s^2) of the stepper
 endstop_pin: ^ar0
 #   Endstop switch detection pin
 homing_speed: 50.0
@@ -75,8 +71,6 @@ step_pin: ar27
 dir_pin: ar26
 enable_pin: !ar25
 step_distance: .0225
-max_velocity: 500
-max_accel: 3000
 endstop_pin: ^ar1
 position_min: -0.25
 position_endstop: 0
@@ -90,8 +84,6 @@ step_pin: ar23
 dir_pin: !ar22
 enable_pin: !ar25
 step_distance: .005
-max_velocity: 250
-max_accel: 30
 endstop_pin: ^ar2
 position_min: 0.1
 position_endstop: 0.5
@@ -108,7 +100,12 @@ dir_pin: ar18
 enable_pin: !ar25
 step_distance: .004242
 max_velocity: 200000
+#   Maximum velocity (in mm/s) of the extruder motor for extrude only
+#   moves.
 max_accel: 3000
+#   Maximum acceleration (in mm/s^2) of the extruder motor for extrude
+#   only moves.
+#
 # The remaining variables describe the extruder heater
 pressure_advance: 0.0
 #   The amount of raw filament to push into the extruder during
@@ -191,6 +188,20 @@ custom:
 [printer]
 kinematics: cartesian
 #   This option must be "cartesian" for cartesian printers
+max_velocity: 500
+#   Maximum velocity (in mm/s) of the toolhead (relative to the
+#   print)
+max_accel: 3000
+#   Maximum acceleration (in mm/s^2) of the toolhead (relative to the
+#   print)
+max_z_velocity: 250
+#   For cartesian printers this sets the maximum velocity (in mm/s) of
+#   movement along the z axis. This setting can be used to restrict
+#   the maximum speed of the z stepper motor on cartesian printers.
+max_z_accel: 30
+#   For cartesian printers this sets the maximum acceleration (in
+#   mm/s^2) of movement along the z axis. It limits the acceleration
+#   of the z stepper motor on cartesian printers.
 motor_off_time: 60
 #   Time (in seconds) of idle time before the printer will try to
 #   disable active motors.