42042 Crawler Crane: conversion to remote control
There's a nice looking mod on Rebrickable that includes full building instructions.



This includes the following PF components:


2 L-Motors - drive
1 M-Motor - tilt cab
1 M-Motor - boom elevation
1 M-Motor - rotate
1 M-Motor - winch
3 IR Receiver
3 IR Remote Control
1 Battery Box