diff --git a/cad/build.py b/cad/build.py
index 8c99bff..f6640a9 100644
--- a/cad/build.py
+++ b/cad/build.py
@@ -90,7 +90,7 @@ def build_drive_shaft_mount():
     return drive_shaft_mount
 
 def build_drive_shaft_bar_adapter():
-    ext_size = 20
+    ext_size = 20.3
     ext_track_width = 6.2
     ext_track_height = 1.8