diff --git a/y2022_bot3/control_loops/drivetrain/BUILD b/y2022_bot3/control_loops/drivetrain/BUILD
index ecdcf6b..3bd4db7 100644
--- a/y2022_bot3/control_loops/drivetrain/BUILD
+++ b/y2022_bot3/control_loops/drivetrain/BUILD
@@ -5,8 +5,10 @@
     outs = [
         "drivetrain_dog_motor_plant.h",
         "drivetrain_dog_motor_plant.cc",
+        "drivetrain_dog_motor_plant.json",
         "kalman_drivetrain_motor_plant.h",
         "kalman_drivetrain_motor_plant.cc",
+        "kalman_drivetrain_motor_plant.json",
     ],
     cmd = "$(location //y2022_bot3/control_loops/python:drivetrain) $(OUTS)",
     target_compatible_with = ["@platforms//os:linux"],
@@ -20,10 +22,13 @@
     outs = [
         "polydrivetrain_dog_motor_plant.h",
         "polydrivetrain_dog_motor_plant.cc",
+        "polydrivetrain_dog_motor_plant.json",
         "polydrivetrain_cim_plant.h",
         "polydrivetrain_cim_plant.cc",
+        "polydrivetrain_cim_plant.json",
         "hybrid_velocity_drivetrain.h",
         "hybrid_velocity_drivetrain.cc",
+        "hybrid_velocity_drivetrain.json",
     ],
     cmd = "$(location //y2022_bot3/control_loops/python:polydrivetrain) $(OUTS)",
     target_compatible_with = ["@platforms//os:linux"],
diff --git a/y2022_bot3/control_loops/python/drivetrain.py b/y2022_bot3/control_loops/python/drivetrain.py
index 7db0a05..a49b8f2 100644
--- a/y2022_bot3/control_loops/python/drivetrain.py
+++ b/y2022_bot3/control_loops/python/drivetrain.py
@@ -36,11 +36,11 @@
 
     if FLAGS.plot:
         drivetrain.PlotDrivetrainMotions(kDrivetrain)
-    elif len(argv) != 5:
-        print("Expected .h file name and .cc file name")
+    elif len(argv) != 7:
+        print("Expected .h, .cc, and .json filenames")
     else:
         # Write the generated constants out to a file.
-        drivetrain.WriteDrivetrain(argv[1:3], argv[3:5], 'y2022_bot3',
+        drivetrain.WriteDrivetrain(argv[1:4], argv[4:7], 'y2022_bot3',
                                    kDrivetrain)
 
 
diff --git a/y2022_bot3/control_loops/python/polydrivetrain.py b/y2022_bot3/control_loops/python/polydrivetrain.py
index 14b9285..13884ee 100644
--- a/y2022_bot3/control_loops/python/polydrivetrain.py
+++ b/y2022_bot3/control_loops/python/polydrivetrain.py
@@ -20,10 +20,10 @@
 def main(argv):
     if FLAGS.plot:
         polydrivetrain.PlotPolyDrivetrainMotions(drivetrain.kDrivetrain)
-    elif len(argv) != 7:
-        glog.fatal('Expected .h file name and .cc file name')
+    elif len(argv) != 10:
+        glog.fatal('Expected .h, .cc, and .json filenames')
     else:
-        polydrivetrain.WritePolyDrivetrain(argv[1:3], argv[3:5], argv[5:7],
+        polydrivetrain.WritePolyDrivetrain(argv[1:4], argv[4:7], argv[7:10],
                                            'y2022_bot3',
                                            drivetrain.kDrivetrain)