Update python models to have accurate constants

This should bring the python models all up to date.  Thanks Sarah for
pulling some of these out of the CAD.

Change-Id: I948685629b8d6835dccd72e623bf110525cb4254
diff --git a/y2020/control_loops/python/drivetrain.py b/y2020/control_loops/python/drivetrain.py
index 54745dd..696c8a2 100644
--- a/y2020/control_loops/python/drivetrain.py
+++ b/y2020/control_loops/python/drivetrain.py
@@ -1,6 +1,7 @@
 #!/usr/bin/python
 
 from frc971.control_loops.python import drivetrain
+from frc971.control_loops.python import control_loop
 import sys
 
 import gflags
@@ -11,11 +12,13 @@
 gflags.DEFINE_bool('plot', False, 'If true, plot the loop response.')
 
 kDrivetrain = drivetrain.DrivetrainParams(
-    J=1.5,
-    mass=38.5,
-    robot_radius=0.45 / 2.0,
-    wheel_radius=4.0 * 0.0254 / 2.0,
-    G=9.0 / 52.0,
+    J=6.0,
+    mass=58.0,
+    # TODO(austin): Measure radius a bit better.
+    robot_radius=0.7 / 2.0,
+    wheel_radius=6.0 * 0.0254 / 2.0,
+    motor_type=control_loop.Falcon(),
+    G=(8.0 / 70.0) * (17.0 / 24.0),
     q_pos=0.14,
     q_vel=1.30,
     efficiency=0.80,