diff --git a/src/components.scad b/src/components.scad
index d4581be..4ac9745 100644
--- a/src/components.scad
+++ b/src/components.scad
@@ -51,6 +51,14 @@ module button_24mm_hole() {
 	cylinder(r=small_button_radius, h=100, $fn=50, center=true);
 }
 
+module frame_hex_bolt_hole() {
+	scale([1, 1, 2]) cylinder(r=m4_bolt_hex_exterior, h=frame_z, $fn=6, center=true);
+}
+
+module frame_interchange_hole() {
+	cylinder(r=15, h=50, $fn=50, center=true);
+}
+
 /* PIECES */
 
 module levermountbase() {
@@ -115,6 +123,10 @@ module topplate() {
 	}
 }
 
+module frame_mount_column() {
+	cube([20, 20, frame_z], center=true);
+}
+
 module frame_panel_surround() {
 	difference() {
 		cube([frame_x, frame_y, top_plate_z], center=true);