add second hole subsubsection and picture

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

diff --git a/curriculum/challenge-bot.scm b/curriculum/challenge-bot.scm
index 32b3020dfa4121be5eff3acc975b8cd0b9df8396..29b24eb0d0e8d63caf8453943a3961aca9c24241 100644 (file)
--- a/curriculum/challenge-bot.scm
+++ b/curriculum/challenge-bot.scm
@@ -250,7 +250,20 @@
                  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.])))
+                 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")))))
    (subsection
     :title [third and fourth hole and screw]))
   (section