: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 [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