✨ POLAR kinematics

MarlinFirmware/Marlin#25214

config/examples/MakerTech3D/Proforge2sDual/Configuration.h

@@ -920,7 +920,7 @@
   #endif
 
   // Print surface diameter/2 minus unreachable space (avoid collisions with vertical towers).
-  #define DELTA_PRINTABLE_RADIUS 140.0    // (mm)
+  #define PRINTABLE_RADIUS       140.0    // (mm)
 
   // Maximum reachable area
   #define DELTA_MAX_RADIUS       140.0    // (mm)
@@ -974,7 +974,7 @@
   #if ENABLED(MORGAN_SCARA)
 
     //#define DEBUG_SCARA_KINEMATICS
-    #define SCARA_FEEDRATE_SCALING  // Convert XY feedrate from mm/s to degrees/s on the fly
+    #define FEEDRATE_SCALING        // Convert XY feedrate from mm/s to degrees/s on the fly
 
     // Radius around the center where the arm cannot reach
     #define MIDDLE_DEAD_ZONE_R   0  // (mm)
@@ -1009,7 +1009,7 @@
   #define TPARA_OFFSET_Y    0       // (mm)
   #define TPARA_OFFSET_Z    0       // (mm)
 
-  #define SCARA_FEEDRATE_SCALING  // Convert XY feedrate from mm/s to degrees/s on the fly
+  #define FEEDRATE_SCALING        // Convert XY feedrate from mm/s to degrees/s on the fly
 
   // Radius around the center where the arm cannot reach
   #define MIDDLE_DEAD_ZONE_R   0  // (mm)
@@ -1019,6 +1019,59 @@
   #define PSI_HOMING_OFFSET    0
 #endif
 
+// @section polar
+
+/**
+ * POLAR Kinematics
+ *  developed by Kadir ilkimen for PolarBear CNC and babyBear
+ *  https://github.com/kadirilkimen/Polar-Bear-Cnc-Machine
+ *  https://github.com/kadirilkimen/babyBear-3D-printer
+ *
+ * A polar machine can have different configurations.
+ * This kinematics is only compatible with the following configuration:
+ *        X : Independent linear
+ *   Y or B : Polar
+ *        Z : Independent linear
+ *
+ * For example, PolarBear has CoreXZ plus Polar Y or B.
+ *
+ * Motion problem for Polar axis near center / origin:
+ *
+ * 3D printing:
+ * Movements very close to the center of the polar axis take more time than others.
+ * This brief delay results in more material deposition due to the pressure in the nozzle.
+ *
+ * Current Kinematics and feedrate scaling deals with this by making the movement as fast
+ * as possible. It works for slow movements but doesn't work well with fast ones. A more
+ * complicated extrusion compensation must be implemented.
+ *
+ * Ideally, it should estimate that a long rotation near the center is ahead and will cause
+ * unwanted deposition. Therefore it can compensate the extrusion beforehand.
+ *
+ * Laser cutting:
+ * Same thing would be a problem for laser engraving too. As it spends time rotating at the
+ * center point, more likely it will burn more material than it should. Therefore similar
+ * compensation would be implemented for laser-cutting operations.
+ *
+ * Milling:
+ * This shouldn't be a problem for cutting/milling operations.
+ */
+//#define POLAR
+#if ENABLED(POLAR)
+  #define DEFAULT_SEGMENTS_PER_SECOND 180   // If movement is choppy try lowering this value
+  #define PRINTABLE_RADIUS 82.0f            // (mm) Maximum travel of X axis
+
+  // Movements fall inside POLAR_FAST_RADIUS are assigned the highest possible feedrate
+  // to compensate unwanted deposition related to the near-origin motion problem.
+  #define POLAR_FAST_RADIUS 3.0f            // (mm)
+
+  // Radius which is unreachable by the tool.
+  // Needed if the tool is not perfectly aligned to the center of the polar axis.
+  #define POLAR_CENTER_OFFSET 0.0f          // (mm)
+
+  #define FEEDRATE_SCALING                  // Convert XY feedrate from mm/s to degrees/s on the fly
+#endif
+
 // @section machine
 
 // Articulated robot (arm). Joints are directly mapped to axes with no kinematics.
@@ -1431,13 +1484,13 @@
   // 2 or 3 sets of coordinates for deploying and retracting the spring loaded touch probe on G29,
   // if servo actuated touch probe is not defined. Uncomment as appropriate for your printer/probe.
 
-  #define Z_PROBE_ALLEN_KEY_DEPLOY_1 { 30.0, DELTA_PRINTABLE_RADIUS, 100.0 }
+  #define Z_PROBE_ALLEN_KEY_DEPLOY_1 { 30.0, PRINTABLE_RADIUS, 100.0 }
   #define Z_PROBE_ALLEN_KEY_DEPLOY_1_FEEDRATE XY_PROBE_FEEDRATE
 
-  #define Z_PROBE_ALLEN_KEY_DEPLOY_2 { 0.0, DELTA_PRINTABLE_RADIUS, 100.0 }
+  #define Z_PROBE_ALLEN_KEY_DEPLOY_2 { 0.0, PRINTABLE_RADIUS, 100.0 }
   #define Z_PROBE_ALLEN_KEY_DEPLOY_2_FEEDRATE (XY_PROBE_FEEDRATE)/10
 
-  #define Z_PROBE_ALLEN_KEY_DEPLOY_3 { 0.0, (DELTA_PRINTABLE_RADIUS) * 0.75, 100.0 }
+  #define Z_PROBE_ALLEN_KEY_DEPLOY_3 { 0.0, (PRINTABLE_RADIUS) * 0.75, 100.0 }
   #define Z_PROBE_ALLEN_KEY_DEPLOY_3_FEEDRATE XY_PROBE_FEEDRATE
 
   #define Z_PROBE_ALLEN_KEY_STOW_1 { -64.0, 56.0, 23.0 } // Move the probe into position