From 5458f3cbd20678ad7db1005e3abf7d01e2099820 Mon Sep 17 00:00:00 2001
From: Kevin O'Connor <kevin@koconnor.net>
Date: Mon, 5 Dec 2016 13:26:26 -0500
Subject: [PATCH] delta: Make sure homing distance is large enough to hit the
 endstop

The head may be far away from an axis at the start of a home, and that
axis must then traverse more than just the distance from zero height
to the endstop position.  Add in additional distance to account for
this.

Signed-off-by: Kevin O'Connor <kevin@koconnor.net>
---
 klippy/delta.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/klippy/delta.py b/klippy/delta.py
index ef7dbde7..19984496 100644
--- a/klippy/delta.py
+++ b/klippy/delta.py
@@ -91,7 +91,7 @@ class DeltaKinematics:
         # Initial homing
         homepos = [0., 0., s.position_endstop, None]
         coord = list(homepos)
-        coord[2] -= 1.5*(s.position_endstop)
+        coord[2] = -1.5 * math.sqrt(self.arm_length2-self.max_xy2)
         homing_state.plan_home(list(coord), homepos, self.steppers
                                , s.homing_speed)
         # Retract