Fix some wrong drivetrain constants.

Change-Id: I40989297b4bf20de68562c99ac7988b6c0034086
diff --git a/y2016/constants.h b/y2016/constants.h
index 87b56cf..3b84c44 100644
--- a/y2016/constants.h
+++ b/y2016/constants.h
@@ -28,12 +28,14 @@
 
   // The ratio from the encoder shaft to the drivetrain wheels.
   static constexpr double kDrivetrainEncoderRatio =
-      (18.0 / 36.0) /*output reduction*/ * (44.0 / 30.0);
+      (18.0 / 36.0) /*output reduction*/ * (30.0 / 44.0) /*encoder gears*/;
 
   // The gear ratios from motor shafts to the drivetrain wheels for high and low
   // gear.
-  static constexpr double kLowGearRatio = 18.0 / 60.0 * 18.0 / 36.0;
-  static constexpr double kHighGearRatio = 28.0 / 50.0 * 18.0 / 36.0;
+  static constexpr double kLowGearRatio =
+      14.0 / 48.0 * 18.0 / 60.0 * 18.0 / 36.0;
+  static constexpr double kHighGearRatio =
+      14.0 / 48.0 * 28.0 / 50.0 * 18.0 / 36.0;
 
   static constexpr double kTurnWidth = 0.601;  // Robot width.
 
diff --git a/y2016/control_loops/python/drivetrain.py b/y2016/control_loops/python/drivetrain.py
index f94b456..94905a2 100755
--- a/y2016/control_loops/python/drivetrain.py
+++ b/y2016/control_loops/python/drivetrain.py
@@ -76,10 +76,10 @@
     self.J = 2.8
     # Mass of the robot, in kg.
     self.m = 68
-    # Radius of the robot, in meters (from last year).
-    self.rb = 0.647998644 / 2.0
+    # Radius of the robot, in meters (requires tuning by hand)
+    self.rb = 0.601 / 2.0
     # Radius of the wheels, in meters.
-    self.r = .04445
+    self.r = 0.097155
     # Resistance of the motor, divided by the number of motors.
     self.resistance = 12.0 / self.stall_current
     # Motor velocity constant
@@ -88,8 +88,8 @@
     # Torque constant
     self.Kt = self.stall_torque / self.stall_current
     # Gear ratios
-    self.G_low = 18.0 / 60.0 * 18.0 / 50.0
-    self.G_high = 28.0 / 50.0 * 18.0 / 50.0
+    self.G_low = 14.0 / 48.0 * 18.0 / 60.0 * 18.0 / 36.0
+    self.G_high = 14.0 / 48.0 * 28.0 / 50.0 * 18.0 / 36.0
     if left_low:
       self.Gl = self.G_low
     else: