choose drill bit to match arduino

diff --git a/curriculum/challenge-bot.scm b/curriculum/challenge-bot.scm
index 2284e0e24a4be0b49c809d3ee24b41fe42b1bbc3..933c0fa080c8e7150f82b11019ddb8be349c0352 100644 (file)
--- a/curriculum/challenge-bot.scm
+++ b/curriculum/challenge-bot.scm
@@ -31,8 +31,12 @@
                   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.])
+                  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