more stuff on offset mesh mech proto

chapter-qkd/chapter.tex

@@ -915,7 +915,7 @@ and axial dimensions as illustrated in Figure\ \ref{qkd_fig_mesh_ring_bearing_to
     angular misalignment of the axis of rotation caused by tolerances in motor bearings in a coaxial labyrinth mesh with
     two tabs. The area swept by each tab, and its increase due to misalignment are highlighted. The left illustration
     shows the ideal and misaligned meshes, and the right illustration superimposes the area increase from the left
-    illustration on the ideally aligned mesh.}
+    illustration on the ideally aligned mesh. This illustration is not to scale.}
     \label{qkd_fig_mesh_ring_bearing_tolerance}
 \end{figure}
 
@@ -931,30 +931,46 @@ and axial dimensions as illustrated in Figure\ \ref{qkd_fig_mesh_ring_bearing_to
 \end{figure}
 
 In QKD applications, the simple disc cover design shown above has two main limitations. First, the distance between the
-primary and secondary meshes must be large enough to allow for the fibers' minimum bend radius, resulting in more than
-\qty{10}{\milli\meter} of space available to an attacker. Second, the attacker only has to bend their tool twice to
-reach the payload. In this section, we will show a design and a mechanical prototype of an offset labyrinth mesh design
-that improves both of these quantities by a large margin.
+primary and secondary meshes' tab rings must be large enough to allow for the fibers' minimum bend radius, resulting in
+more than \qty{10}{\milli\meter} of space available to an attacker. Second, the attacker only has to bend their tool in
+a plane to reach the payload. In this section, we will show a design and a mechanical prototype of an offset labyrinth
+mesh design that improves both of these quantities.
 
-Our offset labyrinth mesh design combines an offset of the secondary mesh's axis of rotation with a three-dimensional
-surface structure on both the inside of the primary mesh, and the facing side of the secondary mesh to create a series
-of narrow, \qty{180}{\degree} turns that an attacker would have to overcome with their tool to reach the payload.
-Structural support is provided using a CNC machined or 3D printed part, which also serves as a conduit for electrical
-connections from the shaft to the payload using Flexible Flat Cable (FFC). While the FFC can easily conform to the
-offset labyrinth's sharp corners, an optical fiber can not. Thus, instead of passing it straight through the labyrinth,
-the payload's fiber optic connections are passed through the labyrinth in a three-dimensional spiral shape, avoiding the
-meshes while simultaneously maximizing the fibers' bend radii.
+\begin{figure}
+    \centering
+    \includegraphics[width=\textwidth]{schema_wire.eps}
+    \caption[Offset labyrinth mesh schema with fiber layout]{\figureattrib{schema_wire.svg}}
+    \label{qkd_fig_offset_lab_fiber}
+\end{figure}
+
+Our offset labyrinth mesh design combines an offset of the secondary mesh's axis of rotation with the labyrinth mesh
+approach from the previous section, creating wide and narrow inter-mesh spaces on alternating sides of the offset
+direction as shown in in Figure\ \ref{qkd_fig_offset_lab_schema}. Structural support is provided using a CNC machined or
+3D printed part, which also serves as a conduit for electrical connections from the shaft to the payload using Flexible
+Flat Cable (FFC). While the FFC can easily conform to the offset labyrinth's sharp corners, an optical fiber can not.
+Thus, instead of passing it straight through the labyrinth, the payload's fiber optic connections are passed through the
+labyrinth in a three-dimensional spiral shape, avoiding the meshes while simultaneously maximizing the fibers' bend
+radii.
+
+To prove the mechanical viability of the offset labyrinth mesh concept, we created a mechanical prototype of one such
+mesh. Figure\ \ref{qkd_fig_offset_lab_fiber} shows the dimensions of the meshes' tabs along with the resulting tab rings
+and a 2D projection of our chosen fiber layout. The fiber is laid out in such a way that it crosses each tab ring at
+opposite sides, and traverses the vertical distance in the larger part of the inter-mesh space. Figures\
+\ref{qkd_fig_lab_mesh_exp_1} and \ref{qkd_fig_lab_mesh_exp_2} show an exploded view of our mechanical prototype from two
+perspectivese, and Figure\ \ref{qkd_fig_lab_mesh_section} shows a section view.
 
 \begin{figure}
     \centering
     \includegraphics[width=\textwidth]{\scaledgraphics{render_exp_1.png}}
     \caption[Offset labyrinth mesh assmbly exploded render]{\figureattrib{render_exp_1.png}}
+    \label{qkd_fig_lab_mesh_exp_1}
 \end{figure}
 
 \begin{figure}
     \centering
     \includegraphics[width=\textwidth]{\scaledgraphics{render_exp_2.png}}
     \caption[Offset labyrinth mesh assmbly exploded render]{\figureattrib{render_exp_2.png}}
+    \label{qkd_fig_lab_mesh_exp_2}
 \end{figure}
 
 \begin{figure}
@@ -962,6 +978,7 @@ meshes while simultaneously maximizing the fibers' bend radii.
     \includegraphics[width=\textwidth]{example-image-10x16.pdf}
     \caption[Offset labyrinth mesh assmbly exploded render, section view]{\draftgraphics\\
     Section view of the labyrinth mesh assembly}
+    \label{qkd_fig_lab_mesh_section}
 \end{figure}
 
 \subsection{Interlocking gear meshes}
@@ -1013,12 +1030,6 @@ meshes do not have to rotate at the same rate of rotation. Instead, harmonic rat
     \caption[Offset overlapping gear mesh schedule]{\figureattrib{gear_plan_2.svg}}
 \end{figure}
 
-\begin{figure}
-    \centering
-    \includegraphics[width=\textwidth]{schema_wire.eps}
-    \caption[Offset labyrinth mesh schema with fiber layout]{\figureattrib{schema_wire.svg}}
-\end{figure}
-
 \section{Outlook}
 
 \clearpage % clearpage flushes all figures. force this here so we don't get figures floating in between references.