We use a Cuisinart ice maker; it's very basic, but relatively convenient. Here's how it works.
There is a heavy bowl that has thick walls and a special gel inside of them that freezes extra hard. (This replaces the rock salt of old-fashioned ice cream makers, which was there to push the temperature below freezing.) The bowl sits on a rotating base and there's a paddle inside the bowl that stirs as the bowl rotates. There's a lid that goes over everything.
This is convenient - no rock salt, no ice, no hand churning. But it has its drawbacks. You can't do more than one batch in a row because the bowl has to be refrozen solid in between. It also produces a very loose ice cream that will need to harden, or cure, in the freezer for another couple hours after churning and before eating.
It's just not as powerful as a more commercial model, but it's loads of fun and we have used ours for everything from catering a wedding party for several hundred people to evening desserts and sorbets. If you have the space and the inclination, this is a great little tool.
Here are some things we've learned about getting the most out of this particular Cuisinart model. These would apply to other frozen-bowl models as well, including the KitchenAid attachment.
Getting the most out of your automatic ice cream maker
• Chill your mix overnight. Really, you have to. The mix should be icy cold before starting.
• Freeze the bowl for at least 24 hours between churning. This is a pain, and the main drawback to these models, but absolutely necessary. You'll be frustrated if the bowl isn't completely rock hard and then some. Hear some sloshing inside when you pick it up? Don't even think about trying to make ice cream yet!
• If you're a heavy user, consider purchasing a second bowl, which you can do through Amazon or Cuisinart's website. Then you can alternate bowls and have a backup in the freezer at all times.
• Chill EVERYTHING. Keep as much as you can frozen at all times. This means the lid and paddle; we have better luck when we've had them in the freezer for a while too.
• Churn longer than you think you need to. For ice cream churn at least 45 minutes. (Sorbets are different; they turn out silkier when churned very briefly - just about 15-20 minutes.)
Where to buy an ice cream maker
Try these Amazon links, but also look at places like Bed Bath & Beyond where a 20% coupon plus a sale can net you one for $30 or under.
• Cuisinart 1-1/2-Quart Automatic Ice Cream Maker, White, $49.95 at Amazon
• Cuisinart 1-1/2-Quart Automatic Ice Cream Maker, Red, $43.99 at Amazon