I understand that an ice cream machine allows you to continue churning it while keeping it cold. To get a smooth ice cream, you need to continually stir it to prevent large ice crystals from forming. You can get the same results by taking it out of a freezer every few minutes, stirring it, and putting it back in. A lot more work, and it will waste a lot of electricity (better to use a chest freezer to minimize waste when opening the door).
b.t.w. I was in Renfrew last Sunday, and stumbled across Tracy's Ice Cream factory on a small dead-end residential street I had never been on before. They have a retail outlet at the front. My first cone of the year was Tin Roof.