winch: Add experimental support for cable winch kinematics

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

config/example-winch.cfg

@@ -0,0 +1,96 @@
+# This file serves as documentation for config parameters of cable
+# winch style printers. One may copy and edit this file to configure a
+# new cable winch printer.
+
+# CABLE WINCH SUPPORT IS EXPERIMENTAL - PROCEED WITH CAUTION!
+
+# Homing is not implemented on cable winch kinematics. In order to
+# home the printer, manually send movement commands until the toolhead
+# is at 0,0,0 and then issue a G28 command.
+
+# Only parameters unique to cable winch printers are described here -
+# see the "example.cfg" file for description of common config
+# parameters.
+
+# The stepper_a section describes the stepper connected to the first
+# cable winch. A minimum of 3 and a maximum of 26 cable winches may be
+# defined (stepper_a to stepper_z) though it is common to define 4.
+[stepper_a]
+step_pin: ar54
+dir_pin: ar55
+enable_pin: !ar38
+step_distance: .01
+#   The step_distance is the nominal distance (in mm) the toolhead
+#   moves towards the cable winch on each step pulse. This parameter
+#   must be provided.
+anchor_x: 0
+anchor_y: -2000
+anchor_z: -100
+#   The x, y, and z position of the cable winch in cartesian space.
+#   These parameters must be provided.
+
+[stepper_b]
+step_pin: ar60
+dir_pin: ar61
+enable_pin: !ar56
+step_distance: .01
+anchor_x: 2000
+anchor_y: 1000
+anchor_z: -100
+
+[stepper_c]
+step_pin: ar46
+dir_pin: ar48
+enable_pin: !ar62
+step_distance: .01
+anchor_x: -2000
+anchor_y: 1000
+anchor_z: -100
+
+[stepper_d]
+step_pin: ar36
+dir_pin: ar34
+enable_pin: !ar30
+step_distance: .01
+anchor_x: 0
+anchor_y: 0
+anchor_z: 3000
+
+[extruder]
+step_pin: ar26
+dir_pin: ar28
+enable_pin: !ar24
+step_distance: .0022
+nozzle_diameter: 0.400
+filament_diameter: 1.750
+heater_pin: ar10
+sensor_type: ATC Semitec 104GT-2
+sensor_pin: analog13
+control: pid
+pid_Kp: 22.2
+pid_Ki: 1.08
+pid_Kd: 114
+min_temp: 0
+max_temp: 250
+
+[heater_bed]
+heater_pin: ar8
+sensor_type: EPCOS 100K B57560G104F
+sensor_pin: analog14
+control: watermark
+min_temp: 0
+max_temp: 130
+
+# Print cooling fan (omit section if fan not present).
+#[fan]
+#pin: ar9
+
+[mcu]
+serial: /dev/ttyACM0
+pin_map: arduino
+
+[printer]
+kinematics: winch
+#   This option must be "winch" for cable winch printers.
+max_velocity: 300
+max_accel: 3000