Add the Drill
For the drill, draw a rectangle that is almost as long as the boom. Connect this rectangle to the top of the boom by two very thin bars for cables. Add a cuff on top of the rectangle, just below the cables.
Draw two more cuff-like structures, one at the bottom of the rectangle and another a little above the first. Below the bottom cuff, draw the drill bit. At the very bottom, add a pointed shape.