fix the frame support box again

math is even harder when you're not using the right variables

src/components.scad

@@ -214,7 +214,7 @@ module topplate_with_raised_overhang() {
 module frame_box() {
 	difference() {
 		roundedcube([frame_x, frame_y, frame_z], center=true, radius=3);
-		cube([frame_x-(panel_support_width*2), frame_y-(panel_support_width*2), frame_z+5], center=true);
+		cube([top_plate_x-(panel_support_width*2), top_plate_y-(panel_support_width*2), frame_z+5], center=true);
 	}
 }