diff --git a/src/frame-piece-side-extended-to-bottom.scad b/src/frame-piece-side-extended-to-bottom.scad
index 4965657..7b9b4b2 100644
--- a/src/frame-piece-side-extended-to-bottom.scad
+++ b/src/frame-piece-side-extended-to-bottom.scad
@@ -5,7 +5,7 @@
 
 include <parameters.scad>
 include <components.scad>
-use <frame-piece-bottom-left-or-right-extended.scad>
+use <frame-piece-top-or-bottom-extended.scad>
 use <frame-piece-side.scad>
 
 module side_and_bottom_frame_piece_wall() {
diff --git a/src/frame-piece-side.scad b/src/frame-piece-side.scad
index 4ccead2..88148cf 100644
--- a/src/frame-piece-side.scad
+++ b/src/frame-piece-side.scad
@@ -5,8 +5,7 @@
 
 include <parameters.scad>
 include <components.scad>
-use <frame-piece-top-left-or-right.scad>
-use <frame-piece-bottom-left-or-right.scad>
+use <frame-piece-top-or-bottom.scad>
 
 module side_frame_piece() {
 	piece_width = panel_support_width+frame_wall+frame_mount_column_width;
@@ -14,8 +13,8 @@ module side_frame_piece() {
 		// side piece is left/right agnostic
 		frame();
 		// minus the top and bottom
-		top_left_or_right_frame_piece();
-		bottom_left_or_right_frame_piece();
+		top_or_bottom_frame_piece();
+		rotate([180, 0, 0]) top_or_bottom_frame_piece();
 		// and just chop out the rest of the frame
 		translate([piece_width, 0, 0]) cube([frame_x, frame_y+1, frame_z+1], center=true);
 	}
diff --git a/src/frame-piece-top-left-or-right.scad b/src/frame-piece-top-or-bottom-aux-and-neutrik.scad
similarity index 78%
rename from src/frame-piece-top-left-or-right.scad
rename to src/frame-piece-top-or-bottom-aux-and-neutrik.scad
index afbc67d..5d88c6f 100644
--- a/src/frame-piece-top-left-or-right.scad
+++ b/src/frame-piece-top-or-bottom-aux-and-neutrik.scad
@@ -7,7 +7,7 @@ include <parameters.scad>
 include <components.scad>
 use <frame-left.scad>
 
-module top_left_or_right_frame_piece() {
+module top_or_bottom_aux_and_neutrik_frame_piece() {
 	piece_width = panel_support_width+frame_wall+frame_mount_column_width;
 	intersection() {
 		left_frame();
@@ -18,9 +18,9 @@ module top_left_or_right_frame_piece() {
 			translate([-frame_x/2+frame_wall/2, 0, 0])
 				cube([frame_wall, frame_y, frame_z], center=true);
 			// ...minus a slot for the combining piece to go into
-			cube([frame_x, frame_y-(panel_support_width+frame_wall)*2, frame_z/4], center=true);
+			cube([frame_x, frame_y-(panel_support_width+frame_wall)*2, inner_frame_z/3], center=true);
 		}
 	}
 }
 
-top_left_or_right_frame_piece();
+top_or_bottom_aux_and_neutrik_frame_piece();
diff --git a/src/frame-piece-bottom-left-or-right-extended.scad b/src/frame-piece-top-or-bottom-extended.scad
similarity index 76%
rename from src/frame-piece-bottom-left-or-right-extended.scad
rename to src/frame-piece-top-or-bottom-extended.scad
index 94bcbfb..d7b25d9 100644
--- a/src/frame-piece-bottom-left-or-right-extended.scad
+++ b/src/frame-piece-top-or-bottom-extended.scad
@@ -5,12 +5,12 @@
 
 include <parameters.scad>
 include <components.scad>
-use <frame-piece-bottom-left-or-right.scad>
+use <frame-piece-top-or-bottom.scad>
 
 module bottom_piece_wall() {
 	// get a slice of the piece, to use it in extruding
 	projection(cut=true) rotate([-90, 0, 0]) translate([0, frame_y/2-frame_bevel_height, 0])
-		bottom_left_or_right_frame_piece();
+		top_or_bottom_frame_piece();
 }
 
 module bottom_piece_extension() {
@@ -21,9 +21,9 @@ module bottom_piece_extension() {
 	}
 }
 
-module extended_bottom_left_or_right_frame_piece() {
-	bottom_left_or_right_frame_piece();
+module extended_top_or_bottom_frame_piece() {
+	top_or_bottom_frame_piece();
 	translate([0, -frame_y/2+frame_bevel_height*2, 0]) rotate([90, 0, 0]) bottom_piece_extension();
 }
 
-extended_bottom_left_or_right_frame_piece();
+extended_top_or_bottom_frame_piece();
diff --git a/src/frame-piece-bottom-left-or-right.scad b/src/frame-piece-top-or-bottom.scad
similarity index 80%
rename from src/frame-piece-bottom-left-or-right.scad
rename to src/frame-piece-top-or-bottom.scad
index e237ca5..3c75548 100644
--- a/src/frame-piece-bottom-left-or-right.scad
+++ b/src/frame-piece-top-or-bottom.scad
@@ -7,7 +7,7 @@ include <parameters.scad>
 include <components.scad>
 use <frame-left.scad>
 
-module bottom_left_or_right_frame_piece() {
+module top_or_bottom_frame_piece() {
 	piece_width = panel_support_width+frame_wall+frame_mount_column_width;
 	intersection() {
 		left_frame();
@@ -18,9 +18,9 @@ module bottom_left_or_right_frame_piece() {
 			translate([-frame_x/2+frame_wall/2, 0, 0])
 				cube([frame_wall, frame_y, frame_z], center=true);
 			// ...minus a slot for the combining piece to go into
-			cube([frame_x, frame_y-(panel_support_width+frame_wall)*2, frame_z/4], center=true);
+			cube([frame_x, frame_y-(panel_support_width+frame_wall)*2, inner_frame_z/3], center=true);
 		}
 	}
 }
 
-bottom_left_or_right_frame_piece();
+top_or_bottom_frame_piece();
diff --git a/src/parameters.scad b/src/parameters.scad
index 0ddb9cb..314881f 100644
--- a/src/parameters.scad
+++ b/src/parameters.scad
@@ -67,6 +67,9 @@ panel_x = frame_x - (frame_wall * 2);
 panel_y = frame_y - (frame_wall * 2);
 panel_z = 5;
 
+// inside the frame
+inner_frame_z = frame_z - (panel_z * 2);
+
 // how much the top plate x/y is expanded to overhang the frame
 // note that this is relative to the top plate (so the wall is added back)
 panel_overhang_amount = 8.5;