diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index f616fda..85a6f45 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -9,6 +9,7 @@ Build_STL:
     - openscad -o horizontal_angle_bracket.stl horizontal_angle_bracket.scad
     - openscad -o ZMotorHalter.stl ZMotorHalter.scad
     - openscad -o SliderRight.stl SliderRight.scad
+    - openscad -o Slider.stl Slider.scad
   artifacts:
     expire_in: 2 days
     paths:
diff --git a/Holes.scad b/Holes.scad
new file mode 100644
index 0000000..f432573
--- /dev/null
+++ b/Holes.scad
@@ -0,0 +1,10 @@
+M3HoleDiam = 3.4;
+M4HoleDiam = 4.4;
+
+module M3Hole(thickness) {
+    rotate([0, 90, 0]) cylinder(h = thickness, d = M3HoleDiam);
+}
+
+module M4Hole(thickness) {
+    rotate([0, 90, 0]) cylinder(h = thickness, d = M4HoleDiam);
+}
\ No newline at end of file
diff --git a/Motorhalter.scad b/Motorhalter.scad
index 23107f7..8aea98d 100644
--- a/Motorhalter.scad
+++ b/Motorhalter.scad
@@ -1,3 +1,5 @@
+use <Holes.scad>;
+
 $fn = 50;
 
 motorheight = 42.1;
@@ -16,7 +18,7 @@ M3HeadDiam = 5.8;
 Motorhalter();
 
 module Motorhalter() {
-    render() difference() {
+    difference() {
         mainbody();
         translate([motorwidth, wanddickelinks, 0]) motorholes(wanddickemotor);
         leftholes();
@@ -39,13 +41,13 @@ module motorholes(thickness) {
     translate([0, motorheight / 2, motorheight / 2])rotate([0, 90, 0])cylinder(h = thickness, d = cylinderdiameter,
     $fn = 130);
 
-    translate([0, motorheight - motorholedistance, motorheight - motorholedistance]) MotorM3Hole(thickness);
+    translate([0, motorheight - motorholedistance, motorheight - motorholedistance]) M3Hole(thickness);
 
-    translate([0, motorheight - motorholedistance, motorholedistance]) MotorM3Hole(thickness);
+    translate([0, motorheight - motorholedistance, motorholedistance]) M3Hole(thickness);
 
-    translate([0, motorholedistance, motorheight - motorholedistance]) MotorM3Hole(thickness);
+    translate([0, motorholedistance, motorheight - motorholedistance]) M3Hole(thickness);
 
-    translate([0, motorholedistance, motorholedistance]) MotorM3Hole(thickness);
+    translate([0, motorholedistance, motorholedistance]) M3Hole(thickness);
 }
 
 module leftholes() {
@@ -59,13 +61,10 @@ module leftholes() {
     translate([motorwidth - leftholedist, 0, motorwidth - leftholedist]) LeftM3Hole();
 }
 
-
-module MotorM3Hole(thickness) {
-    rotate([0, 90, 0])cylinder(h = thickness, d = M3HoleDiam);
-}
-
+// todo move this into Holes
 module LeftM3Hole() {
-    rotate([270, 0, 0])cylinder(h = wanddickelinks, d = M3HoleDiam);
+    // rotate([270, 0, 0])cylinder(h = wanddickelinks, d = M3HoleDiam);
+    rotate([270, 0, 90]) M3Hole(wanddickelinks);
     translate([0, wanddickelinks - 3, 0]) rotate([270, 0, 0])cylinder(h = 3, d = M3HeadDiam);
 }
 
diff --git a/Slider.scad b/Slider.scad
new file mode 100644
index 0000000..c784a76
--- /dev/null
+++ b/Slider.scad
@@ -0,0 +1,3 @@
+$fn=50;
+
+cube();
diff --git a/SliderLeft.scad b/SliderLeft.scad
index 9ddf053..5b8e047 100644
--- a/SliderLeft.scad
+++ b/SliderLeft.scad
@@ -1,6 +1,5 @@
 use <Motorhalter.scad>;
-
-M3HoleDiam = 3.4;
+use <Holes.scad>;
 
 MountSize = 40;
 BodyWidth = 55;
@@ -45,16 +44,14 @@ module YRodHoles(){
     translate([55, 30, -12.5]) rotate([0, 90, 0]) #cylinder(h = 6, d = 8);
     
     translate([55, 25, 10]) #union() {
-        cube([6,10,20]);
-        translate([0, 5, 0]) rotate([0, 90, 0]) cylinder(h = 6, d = 10);
-        translate([0, 5, 20]) rotate([0, 90, 0]) cylinder(h = 6, d = 10);
+        // create the ovale hole with the hull of two holes
+        hull() {
+            translate([0, 5, 0]) rotate([0, 90, 0]) cylinder(h = 6, d = 10);
+            translate([0, 5, 20]) rotate([0, 90, 0]) cylinder(h = 6, d = 10);
+        }
     }
 }
 
-module M3Hole(thickness) {
-    rotate([0, 90, 0])cylinder(h = thickness, d = M3HoleDiam);
-}
-
 module MainBody() {
     // left mount plate
     translate([0,0,-5]) cube([5, MountSize, MountSize+10]);
diff --git a/ZMotorHalter.scad b/ZMotorHalter.scad
index f892d2e..39c469e 100644
--- a/ZMotorHalter.scad
+++ b/ZMotorHalter.scad
@@ -1,6 +1,7 @@
 use <Motorhalter.scad>;
+use <Holes.scad>;
+
 $fn = 50;
-M4HoleDiam = 4.4;
 
 height = 42.1;
 thickness = 4;
@@ -11,15 +12,11 @@ difference() {
     
     l = 47;
     r = 64;
-    translate([l, 6]) rotate([0, -90, -90]) #MotorM4Hole(thickness+1);
-    translate([l, height-5]) rotate([0, -90, -90]) #MotorM4Hole(thickness+1);
+    translate([l, 6]) rotate([0, -90, -90]) #M4Hole(thickness+1);
+    translate([l, height-5]) rotate([0, -90, -90]) #M4Hole(thickness+1);
     
-    translate([r, 6]) rotate([0, -90, -90]) #MotorM4Hole(thickness+1);
-    translate([r, height-5]) rotate([0, -90, -90]) #MotorM4Hole(thickness+1);
+    translate([r, 6]) rotate([0, -90, -90]) #M4Hole(thickness+1);
+    translate([r, height-5]) rotate([0, -90, -90]) #M4Hole(thickness+1);
     
-    translate([l+(r-l)/2, height/2]) rotate([0, -90, -90]) #MotorM4Hole(thickness+1);
-}
-
-module MotorM4Hole(thickness) {
-    rotate([0, 90, 0])cylinder(h = thickness, d = M4HoleDiam);
+    translate([l+(r-l)/2, height/2]) rotate([0, -90, -90]) #M4Hole(thickness+1);
 }
\ No newline at end of file