finish description of attaching second screw

[challenge-bot] / curriculum / challenge-bot.scm

diff --git a/curriculum/challenge-bot.scm b/curriculum/challenge-bot.scm
index b44f9895bb34d2423629ac009e98f126e01ae263..f0a9893855f0de51334ea8b91a044ed4a2841fc1 100644 (file)
--- a/curriculum/challenge-bot.scm
+++ b/curriculum/challenge-bot.scm
@@ -234,21 +234,43 @@
                       holding up the arduino?])
            (item [which side of the deck is the top side?]))]))
     (subsubsection
-     :title [assessment]
-     (p [does the arduino stay with the deck when the deck moves?
-              can the arduino board still rotate a few degrees?
-              warning, if you rotate the arduino board too much, you
-              will unscrew it from the deck and you'll have to screw it
-              back in.
-              rotating a few degrees should be ok.]))
+     :title [assessment of the first screw]
+     (itemize
+      (item [,(bold [warning]), if you rotate the arduino board too
+             much,you will unscrew it from the deck and you'll have to
+             screw it back in.
+             rotating a few degrees should be ok.])
+      (item [does the arduino stay with the deck when the deck moves?])
+      (item [can the arduino board still rotate a few degrees?]))))
+   (subsection
+    :title [second hole and screw]
     (subsubsection
      :title [arduino board move relative to deck]
      (p [without any screws, the arduino board can move independently of
-                 the deck.])
-     (p [with the first screw, the arduino can rotate around one point
-              on the deck.])))
-   (subsection
-    :title [second hole and screw])
+                 the deck.
+                 it can translate and rotate freely.
+                 with the first screw, the arduino can rotate around one
+                 point on the deck and can no longer translate much.])
+     (p [the second screw limits rotation a lot.
+             it also makes translation even more difficult.
+             it might even be too small to be detectable by directly
+             looking at it.])
+     (p [to choose where the second hole and screw should go, we should
+            keep in mind that the goal is to attach the deck to the
+            arduino.
+            this means minimizing rotation and translation.
+            the picture below shows that the second hole should be as
+            far as possible from the first hole, since that minimizes
+            rotation.]
+        (figure :legend "arduino to deck / keep holes far apart"
+                (image :file "arduino-to-deck/keep-holes-far-apart.png"))))
+    (subsubsection
+     :title [drilling and attaching second screw]
+     (p [to drill the second hole, follow the same steps as drilling the
+            first hole.
+            hold the arduino down as before, and drill through the hole
+            furthest away from the first hole.
+            then insert and tighten the screw as before.])))
    (subsection
     :title [third and fourth hole and screw]))
   (section