1multmatrix([[1, 0, 0, -20], [0, 1, 0, 30], [0, 0, 1, 0], [0, 0, 0, 1]]) {
2	group() {
3		minkowski(convexity = 0) {
4			difference() {
5				cube(size = [10, 10, 5], center = true);
6				cube(size = [8, 8, 10], center = true);
7			}
8			cylinder($fn = 0, $fa = 12, $fs = 2, h = 1, r1 = 2, r2 = 2, center = false);
9		}
10	}
11}
12multmatrix([[1, 0, 0, 0], [0, 1, 0, 25], [0, 0, 1, 0], [0, 0, 0, 1]]) {
13	group() {
14		minkowski(convexity = 0) {
15			difference() {
16				cube(size = [10, 10, 5], center = false);
17				cube(size = [5, 5, 5], center = false);
18			}
19			cylinder($fn = 0, $fa = 12, $fs = 2, h = 5, r1 = 5, r2 = 5, center = false);
20		}
21	}
22}
23multmatrix([[1, 0, 0, 25], [0, 1, 0, 25], [0, 0, 1, 0], [0, 0, 0, 1]]) {
24	group() {
25		minkowski(convexity = 0) {
26			cube(size = [10, 10, 5], center = false);
27			cylinder($fn = 0, $fa = 12, $fs = 2, h = 5, r1 = 5, r2 = 5, center = false);
28		}
29	}
30}
31multmatrix([[1, 0, 0, 0], [0, 1, 0, 0], [0, 0, 1, 0], [0, 0, 0, 1]]) {
32	minkowski(convexity = 0) {
33		cube(size = [10, 10, 5], center = false);
34	}
35}
36minkowski(convexity = 0);
37minkowski(convexity = 0);
38