+ :title [first hole]
+ (subsubsection
+ :title [choosing drill bit]
+ (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.])
+ (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]
+ (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.]
+ (figure :legend "arduino to deck / place arduino"
+ (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"))
+ [the picture above shows where to place the arduino on the deck.
+ the arduino should line up with the holes on the deck.
+ this alignment line is highlighted in pink.
+ on the arduino, there's a hole on the top left, between the
+ orange reset button and black headers.
+ the green circle shows where the hole is.
+ the blue box encloses the arduino hole and two deck holes.
+ place the arduino hole mid-way between the two
+ deck holes.])
+ (p [check
+ ,(itemize
+ (item
+ [should the arduino be upside-down?])
+ (item
+ [what should the upper side of the arduino align with?])
+ (item
+ [why not place the arduino up along the left side of the
+ robot?]))]))
+ (subsubsection
+ :title [drilling practice]
+ (p [strength check]
+ (itemize
+ (item [put on safety goggles])
+ (item [unplug drill])
+ (item [hold drill in one hand])
+ (item [point drill at the ground])
+ (item [point drill at the wall])))
+ (p [steps for drilling into wood block]
+ (itemize
+ (item [plug in the drill])
+ (item [place the drill bit in position])
+ (item [bring the drill up to full speed, and keep it at full
+ speed while lowering and raising the drill])
+ (item [push down until the drill bit has passed through an inch
+ of the wood block])
+ (item [keep the drill at full speed])
+ (item [stop before the drill smashes into the wood block])
+ (item [keep the drill at full speed by holding the trigger])
+ (item [bring the drill straight back up])
+ (item [hold the trigger down to keep the drill at full speed])
+ (item [once the drill is back out of the hole, let go of the
+ trigger])))
+ (p [check
+ ,(itemize
+ (item
+ [should the drill be at full speed while the drill bit is
+ going down into the wood and coming back up?])
+ (item
+ [how do you keep the drill at full speed?])
+ (item
+ [what would happen if the drill bit were not at full
+ speed?])
+ (item
+ [what would happen if the drill were twisted sideways while
+ the drill bit were in the wood?]))]))
+ (subsubsection
+ :title [drilling screw hole]
+ (itemize
+ (item [place the drill bit in position])
+ (item [bring the drill up to full speed, and keep it full speed])
+ (item [push down until the drill bit has passed through the
+ deck])
+ (item [keep the drill at full speed])
+ (item [stop before the drill smashes into the arduino])
+ (item [keep the drill at full speed by holding the trigger])
+ (item [bring the drill straight back up])
+ (item [hold the trigger down to keep the drill at full speed])
+ (item [once the drill is back out of the hole, let go of the
+ trigger]))
+ (p [check
+ ,(itemize
+ (item
+ [should the drill be at full speed while the drill bit is
+ going down into the wood and coming back up?])
+ (item
+ [what would happen if the drill bit were not at full
+ speed?])
+ (item
+ [how do you keep the drill at full speed?]))])))
+ (subsection
+ :title [first screw]
+ (subsubsection
+ :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.]
+ (figure :legend "arduino to deck / #6-32 screw"
+ (image :file
+ "arduino-to-deck/6-32-screw.png")))
+ (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
+ 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 after that.])
+ (p [the arduino should still be flat against the deck still, just
+ as it was before tightening the screw.]))
+ (subsubsection
+ :title [assessment]
+ (p [does the arduino stay with the deck when the deck moves?
+ 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.]))
+ (subsubsection
+ :title [arduino board move relative to deck]
+ (p [without any screws, the arduino board can move independently of
+ the deck.])
+ (p [with the first screw, the arduino can rotate around one point
+ on the deck.])))