import cadquery as cq
w0=cq.Workplane('XY',origin=(0,0,-27))
r=w0.sketch().segment((-50,-20),(-40,-36)).segment((0,-11)).arc((6,-10),(10,-5)).segment((50,20)).segment((40,36)).segment((0,11)).arc((-6,10),(-10,5)).close().assemble().finalize().extrude(54)