diff --git a/openscad/own/supermicro_cs836_fan-holder/fanholder_34mm_rear.stl b/openscad/own/supermicro_cs836_fan-holder/fanholder_34mm_rear.stl
new file mode 100644
index 0000000..4cfcb42
Binary files /dev/null and b/openscad/own/supermicro_cs836_fan-holder/fanholder_34mm_rear.stl differ
diff --git a/openscad/own/supermicro_cs836_fan-holder/fanholder_back.scad b/openscad/own/supermicro_cs836_fan-holder/fanholder_back.scad
index 511c562..18738e3 100644
--- a/openscad/own/supermicro_cs836_fan-holder/fanholder_back.scad
+++ b/openscad/own/supermicro_cs836_fan-holder/fanholder_back.scad
@@ -1,22 +1,46 @@
-// VARS
-old_fan_depth=38;
-fan_dia=80;
-fan_depth=25;
-fan_oversize=10;
-mt=2.5;
-width=fan_dia;
-length=fan_dia;
-hole_dia=4.25;
-hole_offset=4.5;
-depth=old_fan_depth-fan_depth;
-cage_mt=2;
-$fn=100;
-
+// by zeus - zeus@ctdo.de - CC-BY-NC-4.0
+// -> https://www.thingiverse.com/zeus
+// -> https://github.com/zeus86
+// -> https://blog.tastatursport.de/
+// 2021-05-16
+// Supermicro Fan-Guard for CSE-836
 //##################
-
+// This Bracket is designed for a Supermicro CSE-836 (3U) Case, 
+// but will most likely fit others as well. If you plan to use anything 
+// else, than the stock turbines, you most likely want to swap fans.
+// This bracket is designed to bridge the gap, which occurs, when 
+// using narrower Fans than stock, e.G. standard ones with 25mm depth.
+// For 25mm fans, set "old_fan_depth" to 34 and use the rear exhaust
+// module, for the center fanwall use 38mm and the fanwall module. 
+// These should fit then with a very slight gap to accomodate the 
+// I/O-Shielding. There are 2 different Models, because the rear ones
+// must not overshoot the original bracket in height in order for the 
+// case top to be able to be closed. These are meant to Replace the 
+// fans FAN-0062L4 (rear) and the fanholder bracket 05-SC93304-XX00C002
+// as well as FAN-0094L4 (center-) with the bracket 05-SC82508-XX00C003.
+// I swapped in 80x80x25mm fans, which works fine.
+//
+//##################
+//
+// VARS
+old_fan_depth=34;       // height of the fan, which is goint to be replaced
+fan_dia=80;             // fan diameter
+fan_depth=25;           // desired fan-depth, most likely 25mm unless you use server-fans
+fan_oversize=10;        // more headroom for the radial area
+mt=2.5;                 // general material thickness, the wall will be slightly thinner on the rear-model, because it needs to be moved inwards
+width=fan_dia;
+length=fan_dia; 
+hole_dia=4.25;          // diameter for the screw holes. I designed them with a slight slope for easy insertion
+hole_offset=4.5;        // x and y offst of the screw-holes from the corner (centered), 4.5mm for 80mm fans
+depth=old_fan_depth-fan_depth; // the difference to be gapped
+cage_mt=2;              //roughly the material thickness of the cage
+screw_clearance=2;      //clearance in the Wall for the screw head
+$fn=100;
+//
+//##################
+//
 // MODEL
-
-module bracket_bottom(){
+module bracket_fanwall(){
     difference(){
         cube([width,length,mt]);
         translate([fan_dia/2,fan_dia/2,-0.1])cylinder(r=(fan_dia+fan_oversize)/2,h=depth+0.2);
@@ -29,4 +53,24 @@ module bracket_bottom(){
     translate([-cage_mt,-mt,0])cube([length+cage_mt*2,mt,depth]);
 }
 
-bracket_bottom();
+module bracket_rear_exhaust(){
+    difference(){
+        cube([width,length,mt]);
+        translate([fan_dia/2,fan_dia/2,-0.1])cylinder(r=(fan_dia+fan_oversize)/2,h=depth+0.2);
+        translate([-0.1,length/2+0.1,-0.1])cube([width+0.2,(length+0.1)/2,depth+0.2]);
+        translate([length/2,hole_offset,-0.1]){
+            translate([-length/2+hole_offset,0,0])cylinder(r1=hole_dia/2,r2=hole_dia/2+0.5,h=mt+0.2);
+            translate([length/2-hole_offset,0,0])cylinder(r1=hole_dia/2,r2=hole_dia/2+0.5,h=mt+0.2);
+        }
+    }
+    difference(){
+        translate([0,0,0])cube([length,mt*0.85,depth]);
+        translate([length/2,hole_offset,0]){
+            translate([-length/2+hole_offset,0,mt])cylinder(r=hole_dia/2+screw_clearance,h=depth-mt+0.2);
+            translate([length/2-hole_offset,0,mt])cylinder(r=hole_dia/2+screw_clearance,h=depth-mt+0.2);
+        }
+    }
+}
+
+//bracket_fanwall();
+bracket_rear_exhaust();