I have a circular wall segment and want to be able to change its radius. To keep the ends squared off I need the create a dmPerpendicular3d constraint between one of the major cylindrical faces and these minor faces. But I can't get this to work. If two face are selected the dmPerpendicular3d constraint immediately shows as 'Unsatisfied'. The alternative of selecting two edges seems to work initially, but fails when the radius is changed.
Am I missing something, or is this not possible without an additional 'helper' solid (pie-segment)?