diff --git a/lower_case.png b/lower_case.png
index d3b73a3..edc7a56 100644
Binary files a/lower_case.png and b/lower_case.png differ
diff --git a/lower_case.scad b/lower_case.scad
index adf56ed..1db8498 100644
--- a/lower_case.scad
+++ b/lower_case.scad
@@ -44,6 +44,12 @@ color("SaddleBrown") difference() {
     translate([pololu_width/2-pololu_hole_spacing, pololu_depth/2-pololu_hole_spacing, -pcb_thickness/2-2]) cylinder(h=2, r=pololu_holes_radius);
   }
   
+  // TODO: make dependent on case size
+  translate([65,26.75,case_bottom_thickness/2]) {
+    cube([10,40,case_bottom_thickness/2+1]);
+    cube([72,10,case_bottom_thickness/2+1]);
+  }
+  
   // screw holes for upper case
   translate([-case_thickness, -case_thickness, 0]) cylinder(h=2, d=4);
   translate([pcb_width-2*pcb_radius+case_thickness, -case_thickness, 0]) cylinder(h=2, d=4);
@@ -56,6 +62,7 @@ color("SaddleBrown") difference() {
   translate([pcb_width-2*pcb_radius+case_thickness, pcb_depth-2*pcb_radius+case_thickness, 0]) cylinder(h=case_thickness+standoff_height+pcb_thickness+5, d=2);
 }
 
+
 // mounting standoffs
 color("SaddleBrown") for(i = [0 : len(mounting_holes)-1]) {
   translate([mounting_holes[i][0] - pcb_radius, mounting_holes[i][1] - pcb_radius, case_bottom_thickness]) difference() {