If you are talking JUST a handwheel and not a hand crank, then the answer is no. Nothing else holds them on. They must be free to spin otherwise you will not be able to wind bobbins without "sewing" or at least having the needle and feed dogs moving. Try some penetrating oil (or kerosene, or hydraulic oil) leave it over night, if that is not enough try some heat (powerful hairdryer or a real heat gun. Also try to get it spinning first. Hold the needle bar and try to turn the wheel.