From 71b4923208b0fda7810d923ae8e2a178030eebac Mon Sep 17 00:00:00 2001
From: Kevin O'Connor <kevin@koconnor.net>
Date: Thu, 1 Dec 2016 16:04:48 -0500
Subject: [PATCH] delta: Support limiting the maximum velocity of z moves

On a delta printer, z moves require the mcu to support the greatest
number of steps per second.  However, z moves are rare, so it makes
sense to limit the velocity of z moves separately from the velocity of
normal xy moves.

Signed-off-by: Kevin O'Connor <kevin@koconnor.net>
---
 config/example-delta.cfg | 7 ++++++-
 klippy/delta.py          | 3 +++
 2 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/config/example-delta.cfg b/config/example-delta.cfg
index 5954be68..c2a46db0 100644
--- a/config/example-delta.cfg
+++ b/config/example-delta.cfg
@@ -79,8 +79,13 @@ pin_map: arduino
 [printer]
 kinematics: delta
 #   This option must be "delta" for linear delta printers
-max_velocity: 200
+max_velocity: 300
 max_accel: 3000
+max_z_velocity: 200
+#   For delta printers this limits the maximum velocity (in mm/s) of
+#   moves with z axis movement. This setting can be used to reduce the
+#   maximum speed of up/down moves (which require a higher step rate
+#   than other moves on a delta printer).
 delta_arm_length: 333.0
 #   Length (in mm) of the diagonal rods that connect the linear axes
 #   to the print head
diff --git a/klippy/delta.py b/klippy/delta.py
index 3b2ad674..ef7dbde7 100644
--- a/klippy/delta.py
+++ b/klippy/delta.py
@@ -14,6 +14,7 @@ class DeltaKinematics:
             printer, config.getsection('stepper_' + n), n)
                          for n in ['a', 'b', 'c']]
         self.need_motor_enable = True
+        self.max_z_velocity = config.getfloat('max_z_velocity', 9999999.9)
         radius = config.getfloat('delta_radius')
         arm_length = config.getfloat('delta_arm_length')
         self.arm_length2 = arm_length**2
@@ -122,6 +123,8 @@ class DeltaKinematics:
         if end_pos[2] > self.limit_z:
             if end_pos[2] > self.max_z or xy2 > (self.max_z - end_pos[2])**2:
                 raise homing.EndstopMoveError(end_pos)
+        if move.axes_d[2]:
+            move.limit_speed(self.max_z_velocity, 9999999.9)
     def move_z(self, move_time, move):
         if not move.axes_d[2]:
             return