diff --git a/scad.sh b/scad.sh
new file mode 100644
index 0000000..eeb2ae4
--- /dev/null
+++ b/scad.sh
@@ -0,0 +1,7 @@
+#!/bin/bash
+
+bash ./scad/common/scad.sh ./scad/bolex_matte_box.scad
+
+mv ./stl/bolex_matte_box_default.stl ./stl/bolex_matte_box.stl
+mv ./img/bolex_matte_box_default.jpg ./img/bolex_matte_box.jpg
+
diff --git a/scad/bolex_matte_box.scad b/scad/bolex_matte_box.scad
index b44ca3b..2084f8e 100644
--- a/scad/bolex_matte_box.scad
+++ b/scad/bolex_matte_box.scad
@@ -1,4 +1,5 @@
 use <./common/common.scad>;
+use <./knobs/scad/knob.scad>;
 
 RAIL_SPACING_HALF_IN = 30;
 HALF_IN_RAIL_D = 13;
@@ -69,5 +70,10 @@ module bolex_matte_box () {
 	matte_box();
 }
 
-bolex_matte_box();
-//rotate([-90, 0, 0]) import("../bolex_matte_box-4x5.5_cards.stl");
\ No newline at end of file
+PART = "default";
+
+if (PART == "default") {
+	bolex_matte_box();
+} else if (PART == "knob") {
+	knob(H = 10, D = 14, DEPTH = 4, BOLT = "M4", TYPE = "hex");
+}
\ No newline at end of file