Two tips: 1) You're likely using an older version of OpenSCAD. Your designs worked for me using the latest development snapshot. 2) The cause of the problems are likely that your cutouts are dimensioned exactly. This may leave infinitely thin walls. It's smart to let cut-outs slightly larger than necessary. -Marius -- View this message in context: http://forum.openscad.org/Attempting-to-fix-my-file-manifold-issue-tp10923p10928.html Sent from the OpenSCAD mailing list archive at Nabble.com.