From 3b2168fea555e259188109719b22b24363299c94 Mon Sep 17 00:00:00 2001
From: Jim Morris <morris@wolfman.com>
Date: Sat, 31 Mar 2018 11:35:39 +0100
Subject: [PATCH] add comment

---
 src/modules/robot/Robot.cpp | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/modules/robot/Robot.cpp b/src/modules/robot/Robot.cpp
index aa28a490..c8e32157 100644
--- a/src/modules/robot/Robot.cpp
+++ b/src/modules/robot/Robot.cpp
@@ -1455,7 +1455,8 @@ bool Robot::append_arc(Gcode * gcode, const float target[], const float offset[]
         return false;
     }
 
-    // Scary math
+    // Scary math.
+    // We need to use arc_milestone here to get accurate arcs as previous machine_position may have been skipped due to small movements
     float center_axis0 = this->arc_milestone[this->plane_axis_0] + offset[this->plane_axis_0];
     float center_axis1 = this->arc_milestone[this->plane_axis_1] + offset[this->plane_axis_1];
     float linear_travel = target[this->plane_axis_2] - this->arc_milestone[this->plane_axis_2];
-- 
2.20.1