diff --git a/app/data/cfg.json b/app/data/cfg.json
index ef6727d..bc96aba 100644
--- a/app/data/cfg.json
+++ b/app/data/cfg.json
@@ -1,5 +1,5 @@
 {
-  "version": "1.8.89",
+  "version": "1.8.90",
   "ext_port": 1111,
   "profiles": {
     "mcopy": {
diff --git a/app/package-lock.json b/app/package-lock.json
index 8344238..e049b8c 100644
--- a/app/package-lock.json
+++ b/app/package-lock.json
@@ -1,6 +1,6 @@
 {
   "name": "mcopy-app",
-  "version": "1.8.89",
+  "version": "1.8.90",
   "lockfileVersion": 2,
   "requires": true,
   "packages": {
diff --git a/app/package.json b/app/package.json
index 1f54cbe..a2973dd 100644
--- a/app/package.json
+++ b/app/package.json
@@ -1,6 +1,6 @@
 {
   "name": "mcopy-app",
-  "version": "1.8.89",
+  "version": "1.8.90",
   "description": "GUI for the mcopy small gauge film optical printer platform",
   "main": "main.js",
   "scripts": {
diff --git a/data/cfg.json b/data/cfg.json
index 1472bc9..f3650ef 100644
--- a/data/cfg.json
+++ b/data/cfg.json
@@ -1,5 +1,5 @@
 {
-  "version": "1.8.89",
+  "version": "1.8.90",
   "ext_port": 1111,
   "profiles": {
     "mcopy": {
diff --git a/package-lock.json b/package-lock.json
index 400891f..57f03ed 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -1,12 +1,12 @@
 {
   "name": "mcopy",
-  "version": "1.8.89",
+  "version": "1.8.90",
   "lockfileVersion": 2,
   "requires": true,
   "packages": {
     "": {
       "name": "mcopy",
-      "version": "1.8.89",
+      "version": "1.8.90",
       "license": "MIT",
       "dependencies": {
         "arduino": "file:app/lib/arduino",
diff --git a/package.json b/package.json
index fa2d2f0..688f854 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "mcopy",
-  "version": "1.8.89",
+  "version": "1.8.90",
   "description": "Small gauge film optical printer platform",
   "main": "build.js",
   "directories": {
diff --git a/processing/mcopy/cfg.json b/processing/mcopy/cfg.json
index ef6727d..bc96aba 100644
--- a/processing/mcopy/cfg.json
+++ b/processing/mcopy/cfg.json
@@ -1,5 +1,5 @@
 {
-  "version": "1.8.89",
+  "version": "1.8.90",
   "ext_port": 1111,
   "profiles": {
     "mcopy": {
diff --git a/scad/cpc_connectors.scad b/scad/cpc_connectors.scad
index db26263..bbd9ef5 100644
--- a/scad/cpc_connectors.scad
+++ b/scad/cpc_connectors.scad
@@ -148,7 +148,19 @@ module cpc_9pin_plug_collar () {
 }
 
 module cpc_9pin_plug_back () {
-	//
+    $fn = FN;
+    RimD = PlugD + 4;
+    difference () {
+        union () {
+            cylinder(r = R(PlugD - 2.7), h = 15, center = true);
+            translate([0, 0, -2.5]) cylinder(r = R(RimD), h = 10, center = true);
+            translate([0, 0, -15 / 2]) sphere(r = R(RimD));
+        }
+        //void
+        cylinder(r = R(PlugD - 5), h = 15 + 1, center = true);
+        translate([0, 0, -15 / 2]) sphere(r = R(PlugD - 5));
+        cylinder(r = R(5), h = 40, center = true);
+    }
 }
 
 module flange_guide_void (pos = [0, 0, 0], Z = 8) {
@@ -212,27 +224,24 @@ module debug () {
 			//color("green") translate([0, 0, 2.1]) rotate([180, 0, 0]) cpc_9pin_socket();
 			cpc_9pin_plug_insert();
 			translate([0, 0, -5]) cpc_9pin_plug_collar();
+            translate([0, 0, -20.5]) cpc_9pin_plug_back();
 		}
 		translate([25, 0, 0]) cube([50, 50, 100], center = true);
 	}
 }
 
-PART="9pin_plug_insert";
+PART = "9pin_plug_back";
 
 if (PART == "9pin_plug") {
-	cpc_9pin_plug();
+	rotate([180, 0, 0]) cpc_9pin_plug();
 } else if (PART == "9pin_plug_insert") {
 	cpc_9pin_plug_insert();
 } else if (PART == "9pin_plug_collar") {
 	cpc_9pin_plug_collar();
+} else if (PART == "9pin_plug_back") {
+    cpc_9pin_plug_back();
 } else if (PART == "9pin_socket") {
 	cpc_9pin_socket();
 } else {
 	debug();
 }
-
-/*
- else if (PART == "9pin_plug_back") {
-	cpc_9pin_plug_back();
-}
-*/
\ No newline at end of file