docs: Improve max_accel documentation in Config_Reference.md

Note that the max_accel parameter is the actual acceleration used in
most movements.

Note that the accel/velocity limits can be changed using the
SET_VELOCITY_LIMIT command.

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

2 files changed, 18 insertions, 7 deletions

diff --git a/docs/Config_Reference.md b/docs/Config_Reference.md
index cc78ddbe..bcccebe0 100644
--- a/docs/Config_Reference.md
+++ b/docs/Config_Reference.md
@@ -88,16 +88,22 @@ kinematics:
 #   deltesian, polar, winch, or none. This parameter must be specified.
 max_velocity:
 #   Maximum velocity (in mm/s) of the toolhead (relative to the
-#   print). This parameter must be specified.
+#   print). This value may be changed at runtime using the
+#   SET_VELOCITY_LIMIT command. This parameter must be specified.
 max_accel:
 #   Maximum acceleration (in mm/s^2) of the toolhead (relative to the
-#   print). This parameter must be specified.
+#   print). Although this parameter is described as a "maximum"
+#   acceleration, in practice most moves that accelerate or decelerate
+#   will do so at the rate specified here. The value specified here
+#   may be changed at runtime using the SET_VELOCITY_LIMIT command.
+#   This parameter must be specified.
 #max_accel_to_decel:
 #   A pseudo acceleration (in mm/s^2) controlling how fast the
 #   toolhead may go from acceleration to deceleration. It is used to
 #   reduce the top speed of short zig-zag moves (and thus reduce
-#   printer vibration from these moves). The default is half of
-#   max_accel.
+#   printer vibration from these moves). The value specified here may
+#   be changed at runtime using the SET_VELOCITY_LIMIT command. The
+#   default is half of max_accel.
 #square_corner_velocity: 5.0
 #   The maximum velocity (in mm/s) that the toolhead may travel a 90
 #   degree corner at. A non-zero value can reduce changes in extruder
@@ -107,7 +113,9 @@ max_accel:
 #   larger than 90 degrees will have a higher cornering velocity while
 #   corners with angles less than 90 degrees will have a lower
 #   cornering velocity. If this is set to zero then the toolhead will
-#   decelerate to zero at each corner. The default is 5mm/s.
+#   decelerate to zero at each corner. The value specified here may be
+#   changed at runtime using the SET_VELOCITY_LIMIT command. The
+#   default is 5mm/s.
 ```
 
 ### [stepper]
diff --git a/docs/G-Codes.md b/docs/G-Codes.md
index 6d492c25..8c70609f 100644
--- a/docs/G-Codes.md
+++ b/docs/G-Codes.md
@@ -1281,8 +1281,11 @@ The toolhead module is automatically loaded.
 
 #### SET_VELOCITY_LIMIT
 `SET_VELOCITY_LIMIT [VELOCITY=<value>] [ACCEL=<value>]
-[ACCEL_TO_DECEL=<value>] [SQUARE_CORNER_VELOCITY=<value>]`: Modify the
-printer's velocity limits.
+[ACCEL_TO_DECEL=<value>] [SQUARE_CORNER_VELOCITY=<value>]`: This
+command can alter the velocity limits that were specified in the
+printer config file. See the
+[printer config section](Config_Reference.md#printer) for a
+description of each parameter.
 
 ### [tuning_tower]