add screw diagram

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

diff --git a/curriculum/challenge-bot.scm b/curriculum/challenge-bot.scm
index 245c149011a9b5760534a6c685f82c0f88b3bb13..eda101bfa79a10125117c744bfbe9774bc2cd516 100644 (file)
--- a/curriculum/challenge-bot.scm
+++ b/curriculum/challenge-bot.scm
@@ -24,7 +24,17 @@
    (subsection
     :title [first hole]
     (subsubsection
-     :title [choosing drill bit])
+     :title [choosing drill bit]
+     (p [choosing the right drill bit depends on what job you are doing.
+                  right now, we are making holes for screws to hold the
+                  arduino to the deck.
+                  this means the hole needs to be big enough for the
+                  screw body to fit through.
+                  we want the screw to stay put once it's in place.
+                  the threads of the screw will grip the edges of the
+                  hole it's going through.])
+     (p [here's a diagram of a screw]
+        (figure :legend "screw" (image :file "arduino-to-deck/screw.png"))))
     (subsubsection
      :title [inserting drill bit])
     (subsubsection