X-Git-Url: http://challenge-bot.com/repos/?a=blobdiff_plain;f=curriculum%2Fchallenge-bot.scm;h=933c0fa080c8e7150f82b11019ddb8be349c0352;hb=8923a50f4be8b08a57995352f6ad5209990c49d0;hp=245c149011a9b5760534a6c685f82c0f88b3bb13;hpb=9fbc1a3fa84c788072a36d6fcf524056dc09366c;p=challenge-bot

diff --git a/curriculum/challenge-bot.scm b/curriculum/challenge-bot.scm
index 245c149..933c0fa 100644
--- a/curriculum/challenge-bot.scm
+++ b/curriculum/challenge-bot.scm
@@ -24,7 +24,21 @@
    (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.
+                  we also want the drill bit to be smaller than the
+                  diameter of the thread.
+                  the screw was chosen so that the hole on the arduino
+                  was bigger than the body and smaller than the thread.
+                  we will choose the biggest drill bit that fits through
+                  the hole on the arduino.])
+     (p [here's a diagram of a screw]
+        (figure :legend "screw" (image :file "arduino-to-deck/screw.png"))))
     (subsubsection
      :title [inserting drill bit])
     (subsubsection
@@ -33,8 +47,8 @@
      :title [arduino placement]
      (p [the arduino should be placed as shown in this picture.]
         (figure :legend "arduino to deck / place arduino"
-                (image :file "arduino-to-deck/3-place-arduino.png"))
-        [here's a closeup]
+                (image :file "arduino-to-deck/3-place-arduino.png")))
+     (p [here's a closeup]
         (figure :legend "arduino to deck / place arduino closeup"
                 (image :file
                        "arduino-to-deck/4-place-arduino-closeup.png"))