clarify sentence on arduino holes

[challenge-bot] / guide / challenge-bot-questions.org

* challenge-bot questions
** mechanical questions
*** arduino to deck
    these questions are about attaching the arduino to the deck.
    you used a drill and drill bit to make holes for bolts to go
    through.
    we drilled through the arduino into the deck.
    1. what would happen if you used a larger drill bit than the one
       you used for drilling holes for the arduino?
    2. why did we use a drill bit that was wider than the body of the
       bolt used to hold the arduino?
    3. why do people use drill bits that are smaller or the same size as
       existing holes in circuit boards, like the holes in the blue
       arduino?
    4. why did we drill through the arduino, rather than marking holes
       and using the drill to make holes where the marks were?
    5. how does the drill hold onto the drill bit?
    6. what would happen if the drill bit teeth were not flat on the
       drill bit?
    7. name some reasons for the arduinos placement on the deck.
       1. could it have been placed diagonally?  why or why not?
       2. could it have been placed in any other location? why or why not?
       3. could it be upside-down?  why or why not?
    8. should we drill at full speed?
       why or why not?
    9. how can you break the drill bit when drilling?
    10. the bolts used to attach the arduino are 6-32 bolts.
        the bolts used to attach the motor to the motor mount are
        4-40 bolts.
        Are the 4-40 bolts fatter or thinner than the 6-32?
    11. if you see a bolt described as =4-40x1.25=" how long is it?
    12. on a =4-40= bolt, how many times does the thread wrap around
        one inch of the body?
        4 times?
        40 times?
        1. how many times does the thread of a =4-40= bolt wrap around
           two inches of the body?
           8 times?
           40 times?
           80 times?
    13. what part of the screw does the screw driver go into?