diff --git a/follow_focus.py b/follow_focus.py
index e919fa9..f9bf855 100644
--- a/follow_focus.py
+++ b/follow_focus.py
@@ -102,7 +102,7 @@ gear_offset=0.5
 base = base.faces('<Z[2]').workplane().circle(large_gear_diameter/2-gear_offset).extrude(gear_thinkness/2)
 base = base.faces('<Z[2]').workplane().circle(2).cutBlind(-part_thinkness/2+wall_width)
 
-lid = lid.faces('>Z[0]').workplane().center(21,-20.15).circle(11/2).extrude(-lid_thicknesss+wall_width)
+lid = lid.faces('>Z[0]').workplane().center(21,-20.15).hLine(t, forConstruction=True).threePointArc((-t,t/2),(0,-t)).polarLine(t, slant_degree).close().extrude(-lid_thicknesss+wall_width)
 lid = lid.faces('>Z[0]').workplane().circle(large_gear_diameter/2-gear_offset).extrude(gear_thinkness/2)
 lid = lid.faces('>Z[0]').workplane().circle(2).cutThruAll()
 m_hole_diameter=6