diff --git a/cad/build.py b/cad/build.py
index 56c3cb8..6bb3de7 100644
--- a/cad/build.py
+++ b/cad/build.py
@@ -68,6 +68,7 @@ def build_drive_shaft_mount():
                 mirror(profile.line, Plane.YZ)
             make_face()
 
+            # TODO: add a seem channel
             with Locations((0, bearing_offset)):
                 Circle(bearing_through_hole_diameter / 2, mode=Mode.SUBTRACT)
 
@@ -75,6 +76,7 @@ def build_drive_shaft_mount():
         mirror(about=Plane.XY)
 
         with Locations((0, bearing_offset, drive_shaft_mount.faces().sort_by(Axis.Z)[-1].center().Z)):
+            # TODO: add a seem channel
             Hole(bearing_diameter / 2, (thickness / 2) + (bearing_height / 2))
             Hole(shaft_clearance_diameter / 2, (thickness / 2) - (bearing_height / 2))
 
@@ -118,6 +120,7 @@ def build_drive_shaft_bar_adapter():
         extrude(amount=height - thickness, mode=Mode.SUBTRACT)
 
         # extrusion screw holes
+        # TODO: remove thin walls on track with a beveled cube cut-out
         with Locations((0, 0, height - ext_screw_hole_offset)):
             with PolarLocations(0, 4):
                 with Locations(Rotation(0, 90, 0)):