outsidenodes=[
/*0*/[s,0,h+x],
/*1*/[s,0,h],
/*2*/[s/2,(s*sqrt(3))/2,h],
/*3*/[-s/2,(s*sqrt(3))/2,h],
/*4*/[-s/2,(s*sqrt(3))/2,h+x],
/*5*/[-s,0,h],
/*6*/[-s/2,-(s*sqrt(3))/2,h],
/*7*/[-s/2,-(s*sqrt(3))/2,h+x],
/*8*/[s/2,-(s*sqrt(3))/2,h],
/*9*/[0,0,h+2*x]

Here is my code for a honeycomb cell: module hexagon(h,s,t,x){ difference(){ linear_extrude (height = h, center = false) circle (s, $fn=6, center = true); linear_extrude (height = h+1, center = false) translate ([0,0,-1]) circle (s-t, $fn=6, center = true); } } module honeycomb (h,s,t,x){ hexagon(h,s,t,x); outsidenodes=[ /*0*/[s,0,h+x], /*1*/[s,0,h], /*2*/[s/2,(s*sqrt(3))/2,h], /*3*/[-s/2,(s*sqrt(3))/2,h], /*4*/[-s/2,(s*sqrt(3))/2,h+x], /*5*/[-s,0,h], /*6*/[-s/2,-(s*sqrt(3))/2,h], /*7*/[-s/2,-(s*sqrt(3))/2,h+x], /*8*/[s/2,-(s*sqrt(3))/2,h], /*9*/[0,0,h+2*x] ]; outsideface=[ [1,0,9,2], [8,9,0,1], [6,7,9,8], [5,9,7,6], [3,4,9,5], [2,9,4,3] ]; union(){ polyhedron (outsidenodes, outsideface) hexagon(h,s,t,x); } union(){ scale ([1-(2*t)/(2*s),1-(2*t)/(2*s),1]) polyhedron (outsidenodes, outsideface); } } honeycomb(10,5,1,(5*sqrt(2))/4); And here is the console output: Compiling design (CSG Tree generation)... Rendering Polygon Mesh using CGAL... PolySet has nonplanar faces. Attempting alternate construction PolySet has nonplanar faces. Attempting alternate construction Geometries in cache: 9 Geometry cache size in bytes: 6624 CGAL Polyhedrons in cache: 4 CGAL cache size in bytes: 186912 Total rendering time: 0 hours, 0 minutes, 4 seconds Top level object is a 3D object: Simple: no Vertices: 33 Halfedges: 128 Edges: 64 Halffacets: 66 Facets: 33 Volumes: 2 WARNING: Object may not be a valid 2-manifold and may need repair! Rendering finished. I am relatively new to this, so any input is appreciated. I am probably missing something pretty basic. How can I merge a polyhedron to an object created with linear_extrude. Is it something wrong with the polyhedron itself? Thanks in advance. -- Sent from: http://forum.openscad.org/