extruder: Calculate sane defaults for extrude only velocity and accel

Instead of requiring the user enter velocity and accel parameters for
extrude only moves, calculate sane defaults from the printer's maximum
velocity and accel.

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

config/avrsim.cfg

@@ -44,8 +44,6 @@ enable_pin: ar25
 step_distance: .004242
 nozzle_diameter: 0.500
 filament_diameter: 3.500
-max_velocity: 200000
-max_accel: 3000
 heater_pin: ar4
 thermistor_pin: analog1
 thermistor_type: EPCOS 100K B57560G104F

config/example-delta.cfg

@@ -48,8 +48,6 @@ enable_pin: !ar24
 step_distance: .0022
 nozzle_diameter: 0.400
 filament_diameter: 1.750
-max_velocity: 200
-max_accel: 3000
 heater_pin: ar10
 thermistor_pin: analog13
 thermistor_type: ATC Semitec 104GT-2

config/example.cfg

@@ -125,12 +125,16 @@ filament_diameter: 3.500
 #   may be. If an extrude only move requests a distance greater than
 #   this value it will cause an error to be returned. The default is
 #   50mm.
-max_velocity: 200000
+#max_extrude_only_velocity:
 #   Maximum velocity (in mm/s) of the extruder motor for extrude only
-#   moves. This parameter must be provided.
-max_accel: 3000
+#   moves. If this is not specified then it is calculated to match the
+#   limit an XY printing move with a max_extrude_cross_section
+#   extrusion would have.
+#max_extrude_only_accel:
 #   Maximum acceleration (in mm/s^2) of the extruder motor for extrude
-#   only moves. This parameter must be provided.
+#   only moves. If this is not specified then it is calculated to
+#   match the limit an XY printing move with a
+#   max_extrude_cross_section extrusion would have.
 #pressure_advance: 0.0
 #   The amount of raw filament to push into the extruder during
 #   extruder acceleration. An equal amount of filament is retracted

config/makergear-m2-2012.cfg

@@ -50,8 +50,6 @@ enable_pin: !PA4
 step_distance: .004242
 nozzle_diameter: 0.350
 filament_diameter: 1.750
-max_velocity: 200000
-max_accel: 3000
 pressure_advance: 0.07
 heater_pin: PH6
 thermistor_pin: PF0

klippy/cartesian.py

@@ -17,7 +17,7 @@ class CartKinematics:
         self.max_z_accel = config.getfloat('max_z_accel', 9999999.9)
         self.need_motor_enable = True
         self.limits = [(1.0, -1.0)] * 3
-    def set_max_jerk(self, max_xy_halt_velocity, max_accel):
+    def set_max_jerk(self, max_xy_halt_velocity, max_velocity, max_accel):
         self.steppers[0].set_max_jerk(max_xy_halt_velocity, max_accel)
         self.steppers[1].set_max_jerk(max_xy_halt_velocity, max_accel)
         self.steppers[2].set_max_jerk(0., self.max_z_accel)

klippy/delta.py

@@ -29,8 +29,7 @@ class DeltaKinematics:
             (cos(210.)*radius, sin(210.)*radius),
             (cos(330.)*radius, sin(330.)*radius),
             (cos(90.)*radius, sin(90.)*radius)]
-    def set_max_jerk(self, max_xy_halt_velocity, max_accel):
-        # XXX - this sets conservative values
+    def set_max_jerk(self, max_xy_halt_velocity, max_velocity, max_accel):
         for stepper in self.steppers:
             stepper.set_max_jerk(max_xy_halt_velocity, max_accel)
     def build_config(self):

klippy/extruder.py

@@ -8,6 +8,7 @@ import stepper, heater, homing
 
 class PrinterExtruder:
     def __init__(self, printer, config):
+        self.config = config
         self.heater = heater.PrinterHeater(printer, config)
         self.stepper = stepper.PrinterStepper(printer, config, 'extruder')
         nozzle_diameter = config.getfloat('nozzle_diameter')
@@ -17,11 +18,15 @@ class PrinterExtruder:
             'max_extrude_cross_section', 4. * nozzle_diameter**2)
         self.max_extrude_ratio = max_cross_section / filament_area
         self.max_e_dist = config.getfloat('max_extrude_only_distance', 50.)
-        self.max_e_velocity = config.getfloat('max_velocity')
-        self.max_e_accel = config.getfloat('max_accel')
+        self.max_e_velocity = self.max_e_accel = None
         self.pressure_advance = config.getfloat('pressure_advance', 0.)
         self.need_motor_enable = True
         self.extrude_pos = 0.
+    def set_max_jerk(self, max_xy_halt_velocity, max_velocity, max_accel):
+        self.max_e_velocity = self.config.getfloat(
+            'max_extrude_only_velocity', max_velocity * self.max_extrude_ratio)
+        self.max_e_accel = self.config.getfloat(
+            'max_extrude_only_accel', max_accel * self.max_extrude_ratio)
     def build_config(self):
         self.heater.build_config()
         self.stepper.set_max_jerk(9999999.9, 9999999.9)

klippy/toolhead.py

@@ -179,7 +179,10 @@ class ToolHead:
         self.motor_off_time = self.reactor.NEVER
         self.flush_timer = self.reactor.register_timer(self._flush_handler)
     def build_config(self):
-        self.kin.set_max_jerk(0.005 * self.max_accel, self.max_accel) # XXX
+        xy_halt = 0.005 * self.max_accel # XXX
+        self.kin.set_max_jerk(xy_halt, self.max_speed, self.max_accel)
+        if self.extruder is not None:
+            self.extruder.set_max_jerk(xy_halt, self.max_speed, self.max_accel)
         self.kin.build_config()
     # Print time tracking
     def update_move_time(self, movetime):