✨ M494 FT_MOTION

Author: thinkyhead

_gcode/M494.md

@@ -0,0 +1,100 @@
+---
+tag: m0494
+title: FT Motion Trajectory Smoothing
+brief: Set / get the Fixed Time Motion parameters for Trajectory and Smoothing.
+author: thinkyhead
+
+group: motion
+requires: FT_MOTION
+since: 2.1.3
+eeprom: true
+
+codes: [ M494 ]
+related: [ M493 ]
+
+parameters:
+
+- tag: T
+  optional: true
+  description: Set trajectory generator type
+  values:
+    - tag: 0
+      description: TRAPEZOIDAL
+    - tag: 1
+      description: POLY5
+    - tag: 2
+      description: POLY6
+
+- tag: O
+  optional: true
+  description: |
+    Set acceleration overshoot for POLY6 (only used when `T=2`).
+    Allowed range: 1.25 – 1.875.
+  values:
+    - type: float
+      tag: overshoot
+
+- tag: X
+  optional: true
+  description: Set smoothing time for the X axis
+  values:
+    - type: float
+      tag: seconds
+
+- tag: Y
+  optional: true
+  description: Set smoothing time for the Y axis
+  values:
+    - type: float
+      tag: seconds
+
+- tag: Z
+  optional: true
+  description: Set smoothing time for the Z axis
+  values:
+    - type: float
+      tag: seconds
+
+- tag: E
+  optional: true
+  description: Set smoothing time for the E axis
+  values:
+    - type: float
+      tag: seconds
+
+examples:
+  - pre: |
+      Set the trajectory generator to a 5‑th order polynomial (POLY5) and enable an
+      acceleration overshoot of 1.50 for the subsequent POLY6 commands.
+    code: M494 T1 O1.5
+
+  - pre: |
+      Set the smoothing time for XYZ axes to 0.25s while leaving E unchanged.
+    code: M494 X0.25 Y0.25 Z0.25
+
+  - pre: |
+      Configure the system for a trapezoidal trajectory generator, with a
+      smoothing time of 0.10s on the X axis and 0.12s on the Y axis.
+    code: M494 T0 X0.10 Y0.12
+
+  - pre: |
+      Use a 6‑th order polynomial (POLY6) with the maximum overshoot of 1.875,
+      and set all axis smoothing times to 0.20s.
+    code: M494 T2 O1.875 X0.20 Y0.20 Z0.20 E0.20
+
+  - pre: |
+      Only change the E‑axis smoothing time to 0.15s, leaving all other
+      parameters at their defaults.
+    code: M494 E0.15
+
+  - pre: |
+      Combine a POLY6 generator with an overshoot of 1.30 and individual
+      smoothing times: X=0.05s, Y=0.07s, Z=0.06s, E=0.04s.
+    code: M494 T2 O1.3 X0.05 Y0.07 Z0.06 E0.04
+---
+
+The `M494` command provides control over the Fixed‑Time Motion trajectory generator, allowing each axis to have its own timing characteristics.
+
+The `T` parameter selects between three generator modes: a simple trapezoidal profile (0), a 5th‑order polynomial (1) that smooths acceleration and deceleration, or a more advanced 6th‑order polynomial (2) that includes an optional acceleration overshoot (`O`) to compensate for system inertia. When `T=2`, the overshoot value may be set between 1.25 and 1.875, giving the printer an additional degree of freedom to maintain speed while preventing jerk.
+
+You can set smoothing times for each of the four motion axes (`X`, `Y`, `Z`, and extruder `E`). These parameters are expressed in seconds and determine how quickly the axis velocity can change, effectively acting as a low‑pass filter on acceleration commands. Adjust these values to balance responsiveness against mechanical wear, achieving smooth, precise motion for complex prints or high‑speed runs.