Well I often train my bis with machines only, same with quads, calves and abs...With chest I usually do some dumbbell presses too and back some deadlifts, not every time though...maybe every other.
Yesterday I did quads in horizontal hack-machine, or wtf it's name is, leg-press and some sissy squats at the end. After that trained hamstrings with leg-curls and one-leg leg-presses. Then calves in hack-machine and a couple of sets seated as well. At the end three sets of abdominal crunches in a machine...That's it. Took me like 40min...and this is a bit of a shame to admit...but my legs were fucking fried after this little machine-pumping.
Rep-range for quads 8-25, hamstrings 4-10, calves 15-30, abs no idea..just pumping a bit. And yes I have front-squatted 200kg~450lbs, just for your interest...Big free weights have their place every once in a while, especially for beginners. But legs are my best bodypart and to be honest the above mentioned is how I usually train..although I like to change it quite often, basically weekly.