[Troublemaker]

It is my understanding that most of these types of self spotters have hooks attached to the bar. You simply twist the bar and it catches on the spotting rack. Probably wouldn't of helped him in the middle of a heart failure. And Nautalis type machines typically can't handle that much weight anyway.

All true, but I do know of some types of Smith machines that have bars that go all the way across and are adjustable and can stop the barbell at various levels. You can set it just above your chest level if you are doing a bench press. You don't get quite the full range of motion (touching the chest) as on a normal bench, but it does fully stop the bar (before it hits you) if you should drop it.

That being said, a spotter is always the best way to lift. I lift with my boys and they are never permitted to lift alone. Terrible story - His doctor probably told him to exercise.

[meyer]

I've got a pair of stands designed specifically for this purpose. I put one on either side of the bench, set to a height just above the chest when I go heavy (and for me, 250# is beyond heavy - I keep my reps high in these golden years). It takes a little care to prevent banging against the stops, but I don't want to get stuck.

I got stuck under 220# once when I was in my mid-20's. I had to roll the weights down to my stomach so that I could sit up and get it onto the floor. Bought the stands soon afterward.