X-Git-Url: http://challenge-bot.com/repos/?a=blobdiff_plain;f=curriculum%2Fchallenge-bot.scm;h=d5fcaf2c9d2c6245a3e05357153aa6a64f538598;hb=1887fb16ccbed28ce710000685987df397e23519;hp=1ae84fda5749200cd3f2468639b0c9db87faa513;hpb=ca8e4428bad920b3941c1a37d63d823f8046eb12;p=challenge-bot

diff --git a/curriculum/challenge-bot.scm b/curriculum/challenge-bot.scm
index 1ae84fd..d5fcaf2 100644
--- a/curriculum/challenge-bot.scm
+++ b/curriculum/challenge-bot.scm
@@ -5,8 +5,10 @@
  :title [challenge-bot]
  (chapter
   :title [mechanical]
+  (p [let's build your robot!])
   (section
    :title [arduino to deck]
+   (p [let's attach the arduino to the deck.])
    (subsection
     :title [required materials]
     (p [you will need the things in this picture.
@@ -20,34 +22,67 @@
               (item [alan wrench])
               (item [wood block])
               (item [arduino])
-              (item [#6-32x3/8\", four of them]))]))
+              (item [#6-32x3/8\", four of them])
+              (item [robot deck, the white thing with a grid of holes1]))]))
    (subsection
     :title [first hole]
     (subsubsection
      :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"))))
+     (p [the arduino comes with holes in it already, so we will make
+             some choices around those holes.
+             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.
+             there are two constraints between the hole and screw.
+             each hole needs to be big enough for the screw body to fit
+             through it.
+             the holes also need to be smaller than the screw's thread.
+             since there are holes on the arduino already, the screw was
+             chosen to match it.
+             the screw was chosen so that the hole on the arduino was
+             bigger than the screw body and smaller than its thread.
+             we will choose the biggest drill bit that fits through the
+             hole on the arduino, then use that to drill holes in the
+             deck.])
+     (p [here's a cross section of a screw in the deck]
+        (figure :legend "screw cross section"
+                (image :file
+                       "arduino-to-deck/screw-cross-section.png")))
+     (p [check
+         ,(itemize
+           (item
+            [what would happen if the drill bit were larger than the
+                  screw thread?])
+           (item
+            [what would happen if the drill bit were smaller than the
+                  screw body?]))]))
     (subsubsection
      :title [inserting drill bit]
      (p (figure :legend "arduino to deck / insert bit"
                 (image :file "arduino-to-deck/1-insert-bit.png"))
         [insert the drill bit into the teeth of the drill.
                 insert it far enough that the teeth will clamp on the
-                smooth part of the bit when they are tightened.]))
+                smooth part of the bit when they are tightened.])
+     (p (figure
+         :legend "arduino to deck / twist tighten drill teeth"
+         (image :file "arduino-to-deck/2-twist-tighten-drill-teeth.png"))
+        [while holding the drill bit, twist end of the drill to tighten
+               the teeth.
+               make sure that the teeth end up gripping the flat part of
+               the drill bit.])
+     (p [check
+         ,(itemize
+           (item
+            [where should the teeth clamp down on the drill bit?])
+           (item
+            [what would happen if the teeth tightened on the recessed
+                  part of the drill bit?]))]))
     (subsubsection
-     :title [holding drill])
+     :title [holding drill]
+     (p [hold the drill with one hand on the handle and trigger.
+              put the other hand on the orange nozzle, before the
+              black spinning part.]))
     (subsubsection
      :title [arduino placement]
      (p [the arduino should be placed as shown in this picture.]
@@ -75,7 +110,10 @@
      (p [the "#6" part of "#6-32x3/8\"" is how big around the bolt is.
              it is related to wire gauge.
              bigger numbers mean larger screw.
-             smaller numbers means smaller screws.])
+             smaller numbers means smaller screws.]
+        (figure :legend "arduino to deck / #6-32 screw"
+                (image :file
+                       "arduino-to-deck/6-32-screw.png")))
      (p [check
          ,(itemize
            (item