Don't use a smith machine. Find a gym with (or buy) a proper squat rack with safety bars that you can adjust to the proper height if you do have to bail out of

Don't use a smith machine. Find a gym with (or buy) a proper squat rack with safety bars that you can adjust to the proper height if you do have to bail out of a squat. With a smith machine, you don't get the full range of motion you have with real barbell squats - it's straight-line up and down. I also am not a fan of the twisting motion you need to perform to get the bar locked in.