diff --git a/.gitmodules b/.gitmodules
new file mode 100644
index 0000000..18f70a7
--- /dev/null
+++ b/.gitmodules
@@ -0,0 +1,3 @@
+[submodule "common"]
+	path = common
+	url = https://git.sixteenmillimeter.com/modules/common.git
diff --git a/common b/common
new file mode 160000
index 0000000..b499c28
--- /dev/null
+++ b/common
@@ -0,0 +1 @@
+Subproject commit b499c2810117b5ca57014d5cb4219cf68b4c5c0f
diff --git a/split_reel.scad b/split_reel.scad
index e69de29..5e62e08 100644
--- a/split_reel.scad
+++ b/split_reel.scad
@@ -0,0 +1,86 @@
+include <./common/common.scad>;
+include <./common/threads.scad>;
+
+Core16mm = 25.5;
+PlatterThickness = 1.6;
+Platter120m = 178;
+
+module thread_16mm ( pos = [0, 0, 0], length = 11, pad = 0) {
+    translate(pos) {
+        metric_thread (diameter=18.5, pitch=1.5, length=length, internal=false, n_starts=1, thread_size=-1, groove=false, square=false, rectangle=0, angle=30, taper=0, leadin=0, leadfac=1.0);
+    }
+}
+
+module threaded_core (pos = [0, 0, 0], format = "16mm") {
+    $fn = 120;
+    translate (pos) {
+        if (format == "16mm") {
+            union () {
+                cylinder(r = R(Core16mm), h = 6, center = true);
+                thread_16mm([0, 0, 6 / 2], length = 11);
+            }  
+        }
+    }
+}
+
+module socket_core (pos = [0, 0, 0], format = "16mm") {
+    $fn = 120;
+    translate (pos) {
+        if (format == "16mm") {
+            difference () {
+                cylinder(r = R(Core16mm), h = 11, center = true);
+            }
+        }
+    }
+}
+
+module platter (pos = [0, 0, 0], length = 120) {
+    if (length == 120) {
+        difference () {
+            cylinder(r = R(Platter120m), h = PlatterThickness, center = true, $fn = 300);
+            for (i = [0 : 3]) {
+                rotate([0, 0, i * 90]) translate([105 / 2, 0, 0]) cylinder(r = R(44.5), h = PlatterThickness + 1, center = true, $fn = 100);
+            }
+        }
+    }
+}
+
+//length in meters
+module split_reel (format = "16mm", length = 120, half = "A") {
+
+    if (half == "A") {
+        difference () {
+            union () {
+                platter([0, 0, 0], length = length);
+                threaded_core([0, 0, (PlatterThickness / 2) + (6 / 2)], format = "16mm");
+            }
+            if (format == "16mm") {
+                cube([8.5, 8.5, 50], center = true);
+                rotate([0, 0, 45]) translate([5.5, 0, 0]) cube([3, 3, 50], center = true);
+            }
+        }
+    } else if (half == "B") {
+        difference () {
+            union () {
+                platter([0, 0, 0], length = length);
+                socket_core([0, 0, (PlatterThickness / 2) + (11 / 2)], format = "16mm");
+            }
+            thread_16mm([0, 0, -1], 15);
+            thread_16mm([0, 0, -1.1], 15);
+        }
+    }
+}
+
+PART = "split_reel_16mm_120m_B";
+
+if (PART == "split_reel_16mm_120m_A") {
+    intersection () {
+        split_reel("16mm", 120, "A");
+        cube([30, 30, 30], center = true);
+    }
+} else if (PART == "split_reel_16mm_120m_B") {
+    intersection () {
+        split_reel("16mm", 120, "B");
+        cube([30, 30, 30], center = true);
+    }
+}
\ No newline at end of file