diff --git a/katzenklappe.scad b/katzenklappe.scad
index 8750680..9365f72 100644
--- a/katzenklappe.scad
+++ b/katzenklappe.scad
@@ -1,3 +1,5 @@
+angle = 10;
+raise = 10;
 tunnel_w = 160;
 tunnel_h = 160;
 tunnel_t = 10; // tunnel thickness
@@ -5,19 +7,35 @@ tunnel_s = 40; // tunnel spacing: overlap for screws
 door_t = 50; // door thickness
 plexy_t = 6; // thickness of plexy glass sheet
 gap = 1; // gap between parts moving relative to each other
-seal = 5;
-angle = 0;
-guide_h = 20;
+seal = 5; // thickness of seal. May be set to gap
+guide_h = 40;
+bearing_inner_dia = 10;
+bearing_outer_dia = 20;
+bearing_h = 5;
+stopper_h = 40;
+stopper_w = 30;
+space = bearing_outer_dia; // space between plexy glass sheets
 
 // calculations
-rad = 3*plexy_t/2;
+rad = (space+2*plexy_t)/2;
 sheet_h = tunnel_h-2*seal-rad;
 
 // colors
 plexy = [0.4,0.6,1,0.6];
+red = [1,0,0];
+green = [0,0.6,0];
+silver = [0.7,0.7,0.7];
 snow = [1,1,1,0.5];
 wood = [0.8,0.3,0];
 
+// constants
+$fn = 32;
+rx = [90,0,0]; // rotate 90 deg around x
+ry = [0,90,0]; // rotate 90 deg around y
+x = [1,0,0];
+y = [0,1,0];
+z = [0,0,1];
+
 module door(){
     color(wood) difference(){
         cube([1000,door_t,2000],true);
@@ -33,30 +51,89 @@ module tunnel(){
     color(snow)difference(){
         union(){
             tunnel_core();
-            translate([0,(door_t+tunnel_t)/2,0])  cube([tunnel_w+2*tunnel_s,tunnel_t,tunnel_h+2*tunnel_s],true); // krempe
-            translate([0,(door_t+tunnel_t)/-2,0]) cube([tunnel_w+2*tunnel_s,tunnel_t,tunnel_h+2*tunnel_s],true); // krempe
+            translate(-y*(door_t+tunnel_t)/2) cube([tunnel_w+2*tunnel_s,tunnel_t,tunnel_h+2*tunnel_s],true); // krempe
+            translate( y*(door_t+tunnel_t)/2) cube([tunnel_w+2*tunnel_s,tunnel_t,tunnel_h+2*tunnel_s],true); // krempe
         }
         cube([tunnel_w,door_t+2*tunnel_t+2,tunnel_h],true); // loch
     }
 }
 
+module screw(){
+    rotate(x*90)cylinder(d=4,h=space+3*plexy_t,center=true);
+}
+
 module sheets(){
-    translate([0,-plexy_t,-sheet_h/2])cube([tunnel_w-2*seal,plexy_t,sheet_h],true);
-    translate([0, plexy_t,-sheet_h/2])cube([tunnel_w-2*seal,plexy_t,sheet_h],true);
+    difference(){
+        union(){
+            translate([0,(space+plexy_t)/2,-sheet_h/2])cube([tunnel_w-2*seal,plexy_t,sheet_h],true);
+            translate([0, (plexy_t+space)/-2,-sheet_h/2])cube([tunnel_w-2*seal,plexy_t,sheet_h],true);
+        }
+        hull(){
+            translate(-z*(sheet_h+10)) rotate(ry) cylinder(d=bearing_outer_dia+2*gap,h=bearing_h+2*gap,center=true);
+            translate(z*(bearing_outer_dia/2-sheet_h)) rotate(ry) cylinder(d=bearing_outer_dia+2*gap,h=bearing_h+2*gap,center=true);
+        }
+    }
+
+}
+
+module guide(){
+    a = guide_h-gap-10;
+    b = 10+gap+stopper_w/2;
+    translate([b, 0,a/2-sheet_h])cube([20,space,a],true);
+    translate([-b, 0,a/2-sheet_h])cube([20,space,a],true);
 
-    translate([0,0,guide_h/2-sheet_h])cube([10,plexy_t,guide_h],true);
+}
+
+module bearing_case(){
+    a = bearing_h/2+gap;
+    rotate(ry) cylinder(d=bearing_inner_dia-gap,h=a);
+    translate([a/2+stopper_w/4,0,stopper_h/2]) cube([stopper_w/2-a,space-2*gap,stopper_h],true);
+    translate([(stopper_w/2+5)/2,0,stopper_h-5]) cube([stopper_w/2+5,space-2*gap,10],true);
+}
+
+module bearing(){
+    color(silver)
+        rotate(ry)
+            difference(){
+                cylinder(d=bearing_outer_dia,h=bearing_h,center=true);
+                cylinder(d=bearing_inner_dia,h=bearing_h+2,center=true);
+            }
+}
+
+module stopper(){
+    color(green) {
+        bearing_case();
+        rotate(z*180)bearing_case();
+    }
+    bearing();
 }
 
 module flap(){
-    translate([0,0,(sheet_h-rad)/2]) rotate([angle,0,0]) union(){
+    b = 10+gap+stopper_w/2;
+    translate(z*(sheet_h-rad)/2) rotate(x*angle) {
         difference(){
-            rotate([0,90,0]) cylinder(d=3*plexy_t,h=tunnel_w-2*seal,center=true);
+            rotate(y*90) cylinder(d=2*rad,h=tunnel_w-2*seal,center=true);
             sheets();
+            translate([tunnel_w/ 4,0,rad/-2])screw();
+            translate([tunnel_w/-4,0,rad/-2])screw();
         }
-        color(plexy)sheets();
+        color(plexy) difference(){
+            union(){
+                sheets();
+                guide();
+            }
+            translate([b,0,5-sheet_h])screw();
+            translate([b,0,guide_h-15-gap-sheet_h])screw();
+            translate([-b,0,5-sheet_h])screw();
+            translate([-b,0,guide_h-15-gap-sheet_h])screw();
+            translate([tunnel_w/ 4,0,rad/-2])screw();
+            translate([tunnel_w/-4,0,rad/-2])screw();
+        }
+        translate(z*(raise-sheet_h))stopper();
     }
 }
 
-*door();
-*tunnel();
+door();
+tunnel();
 flap();
+