add fill option

2 files changed, 19 insertions, 5 deletions

diff --git a/README.md b/README.md
index d3326c7..66a43fb 100644
--- a/README.md
+++ b/README.md
@@ -9,9 +9,11 @@ Create fully parameterized Templates for GridFinity.
 `gridfinity(<x>, <y>, <z>, lip=<>, magnets=<>);`
 
 * **x, y** Vertical size in *GridFinity* units
-* **z** Height in GridFinity units (`z * 7mm`). This in excluding the base and stacking lip.
-* **lip** `true/false` Sets wether to put a stacking lip on top. Only works with z >= 1.
-* **magnets** `true/false` Sets wether to put holes for magnets in the base.
+* **z** Height in GridFinity units (`z * 7mm`). This is excluding the base and stacking lip.
+* **lip** `true/false` Sets wether to put a stacking lip on top. Only works with z >= 1. Default `true`
+* **magnets** `true/false` Sets wether to put holes for magnets in the base. Default `false`
+* **fill** `true/false` Sets wether the created object is solid or hollow. Default `true`
+* **bottom_height** Height offset for floor. Only applicable, if `fill == false`. Default `0`
 
 ## Example
 
diff --git a/gridfinity.scad b/gridfinity.scad
index a26e758..c67fe3c 100644
--- a/gridfinity.scad
+++ b/gridfinity.scad
@@ -148,7 +148,7 @@ module bottom_cutout(units_x, units_y) {
   }
 }
 
-module gridfinity(units_x, units_y, units_z, lip = true, magnets = false) {
+module gridfinity(units_x, units_y, units_z, lip = true, magnets = false, fill = true, bottom_height = 0) {
   units_x = floor(abs(units_x));
   units_y = floor(abs(units_y));
   units_z = floor(abs(units_z));
@@ -167,7 +167,19 @@ module gridfinity(units_x, units_y, units_z, lip = true, magnets = false) {
       linear_extrude(extr)
         rounded_square(units_x * width - 0.5, units_y * width - 0.5, rounding);
     }
-    bottom_cutout(units_x, units_y);
+    union(){
+      bottom_cutout(units_x, units_y);
+
+      // remove solid block if set, leave walls
+      if (! fill) {
+        wall_thickness = 2.95; // thickness of stacking lip
+        extr = units_z * height - (4.75 + minimal_thickness) - bottom_height + 0.01;
+
+        translate([coord_centered(units_x), coord_centered(units_y), 4.75 + minimal_thickness + bottom_height])
+          linear_extrude(extr)
+            rounded_square(units_x * width - wall_thickness * 2, units_y * width - wall_thickness * 2, 0.7);
+      }
+    }
   }
 
   // Stacking Lip