leg curls: 12x 70-90#
leg extensions: 12x 90#, but see below
hip abduction / adduction: 70-90# fairly easily, but see below
seated leg press: 12x 190# was a good challenge.
The hip abduction/adduction and leg extension machines made LiveStrong.com's "10 exercise machines to avoid" list. The criticism of the hip machines is that a seated training position doesn't correspond to real-world motions. They aren't dangerous, but they're essentially a waste of time outside of specific physical-therapy scenarios. The leg extension machine, on the other hand (or foot), is potentially dangerous to the knee; and again, outside of a physical-therapy scenario, isolating the quads is not particularly useful, as they get ample training in squat and leg-press motions. The real trick in lower-body training is to isolate the hamstrings, not the quads. So I'll probably settle on the leg curls and leg press for my machine circuit.
One curious thing I noticed on the hip adduction was that I couldn't do the motion smoothly; the muscles "chatter" as I bring the knees together.
After 1 set calibrating myself on the lower-body stations, I stepped through a set on the upper-body machines, then returned for a second lower-body set.