Sure it is possible. Try to use machines that a spotter is not needed for like plate loaded and such or ones with a built in spotter system. As far as free wieghts are concerned, your going to have to be able to avoid injuries and be able to remove the weights off of you if you decide to not use a spotter. Imo it is safer, for that reason alone (avoiding injury), to use a spotter if your at a gym. If you work out alone and at home, maybe find a buddy who can come over once a week and then you can push to 100% failure or do some assisted reps if you want.