X-Git-Url: http://challenge-bot.com/repos/?a=blobdiff_plain;f=curriculum%2Fchallenge-bot.scm;h=65d56ff9581f768adcdc75c7515e182c785db219;hb=9f6519960b3edc341066a6c9e138a9992fd7eb4d;hp=76dc7781a7133f338a04b10881f3e582af333956;hpb=ff0f6a781b4916b42634677c980935ccddbaad79;p=challenge-bot

diff --git a/curriculum/challenge-bot.scm b/curriculum/challenge-bot.scm
index 76dc778..65d56ff 100644
--- a/curriculum/challenge-bot.scm
+++ b/curriculum/challenge-bot.scm
@@ -10,7 +10,7 @@
    (subsection
     :title [arduino placement])
    (subsection
-    :title [first hole and screw]
+    :title [first hole]
     (subsubsection
      :title [choosing drill bit])
     (subsubsection
@@ -18,24 +18,49 @@
     (subsubsection
      :title [holding drill])
     (subsubsection
-     :title [drilling])
+     :title [drilling]))
+   (subsection
+    :title [first screw]
     (subsubsection
-     :title [6-32 by 3/8\" screw]
-     (p [the "6" part is how big around it is.])
-     (p [the "32" part is how close the threads are to each other.])
-     (p [the "head" is the flat part where some tool, like the alan
-             wrench, can exert force to spin the screw.]))
+     :title [fastening arduino to deck using #6-32x3/8\" screw]
+     (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.])
+     (p [check
+         ,(itemize
+           (item
+            [in the motor assembly, there are #4-40x1.25\" screws.
+                are those fatter, thinner, or the same thickness as the
+                #6-32x3/8\" screws?]))])
+     (p [the "32" part is a measurement of how close the threads are to
+             each other.
+             this is related to the angle of the thread, which is also
+             called pitch.
+             it is a count of how many times the thread wraps around one
+             inch of the screw body.])
+     (p [the head is the flat part where some tool, like the alan
+             wrench, can exert force to spin the screw.])
+     (p [check
+         ,(itemize
+           (item [how many times will the thread wrap around one inch of
+                      the screw body?])
+           (item [what about 2 inches?
+                       how many times will the thread wrap around two
+                       inches of the screw body?]))]))
     (subsubsection
      :title [fasten the arduino board to the deck]
      (p [push the 6-32 screw into the deck from the underside and at the
               same time, spin the 6-32 screw clockwise while looking
-              down on its head.  twist until the bottom of the screw is
+              down on its head.
+              twist until the bottom of the screw is
               about to stick out on the top side of the deck.])
      (p [hold the arduino board flat to the deck and line up the arduino
-              hole so the screw can come up through it.  continue
-              tightening the screw into the deck, spinning the same
-              direction as before.  tighten until the screw head touches
-              the deck.  do not continue tightening])
+              hole so the screw can come up through it.
+              continue tightening the screw into the deck, spinning the same
+              direction as before.
+              tighten until the screw head touches the deck.
+              do not continue tightening after that.])
      (p [the arduino should still be flat against the deck still, just
              as it was before tightening the screw.]))
     (subsubsection
@@ -44,7 +69,8 @@
               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.]))
+              back in.
+              rotating a few degrees should be ok.]))
     (subsubsection
      :title [arduino board move relative to deck]
      (p [without any screws, the arduino board can move independently of