diff --git a/control/walle.py b/control/walle.py
index 538878f..0486cae 100644
--- a/control/walle.py
+++ b/control/walle.py
@@ -66,5 +66,5 @@ class WallE:
         left_right = distance * math.cos(angle)
         minval = 50
         maxval = 130
-        self.servo_controller.write(SERVO_ARM_L, map_range(up_down, 0.0, 1.0, minval, maxval))
-        self.servo_controller.write(SERVO_ARM_R, map_range(left_right, 0.0, 1.0, minval, maxval))
+        self.servo_controller.write(SERVO_ARM_L, map_range(up_down, -1.0, 1.0, minval, maxval))
+        self.servo_controller.write(SERVO_ARM_R, map_range(left_right, -1.0, 1.0, minval, maxval))