// Produce a hollow prism shaped plinth // to hold an acrylic sheet // cavity for LED strip to edge light acrylic module prism(w=30, h=20, l=100, lean=10) { polyhedron( points=[ [0,0,0], [l,0,0], [l,w,0], [0,w,0], [lean,lean,h], [l-lean,lean,h], [l-lean,w-lean,h], [lean,w-lean,h] ], faces=[ [0,2,1], [0,3,2], [0,1,5], [0,5,4], [1,2,6], [1,6,5], [2,3,7], [2,7,6], [0,7,3], [0,4,7], [4,5,6], [4,6,7] ], convexity=4 ); } // thickness of the acrylic sheet (mm) // allow half a mm for sloppiness of print acrylic = 3.0 + 0.5; // Assumes a 100mm width of acrylic // with a 90mm tang to stick in by 10mm or so awidth = 100; // construct the base base = awidth + 20; difference() { // outer prism(30,20,base); // inner cavity #translate([-5,7,2]) prism(w=16, h=10, l=base, lean=(16-acrylic)/2); // gap for tang #translate([15,15-(acrylic/2),10]) cube([awidth-10,acrylic,50]); }