Homemade ice cream has a unique taste which simply isn't duplicated amongst commercial brands. Add to that the large number of flavors one can make, the sense of accomplishment through all things DIY, and of course enjoying your creation and you have a winner with ice cream made at home.
Warning: It has been brought to my attention that only food grade plastics should be used for a project such as this. For this tutorial, that would basically mean replacing the spindle with something designed for use with food. You can never be too safe- especially if you have kids.
Step 1: Gather Materials for Ice Cream Maker
There are really three major parts to this, all of which were found in my home. The most important part is the electric motor which can be salvaged from any number of electronics. This particular one came from a non-working disc drive and the motor was used to open and close the tray. I left the gears attached and just cut the plastic around it so everything stayed intact. Also needed is an empty jar of peanut butter with the lid, and a 100 recordable DVD casing, which needs to be the type where the spindle unscrews from the base as opposed to the type where it is fixed in place. You'll need a few other odds and ends such as a little plastic ring from the stack of recordable DVDs, some cocktail straws, four pieces of short (3-4 inches or so) galvanized wire, and something to secure the motor down later in the process.
Step 2: Make Some Modifications
I was lucky enough to have the electric motor already mounted to something usable, so we'll forget it for now. To start with, I drilled four evenly spaced (eyeballed) holes in the peanut butter jar on the neck of the bottle. I then cut four notches in the DVD case to correspond. Not too deep, just enough you can hang a piece of wire over the edge without interfering with attaching the base again. I then ran some wire through the holes and hung the peanut butter jar inside the upside down DVD case. Finally, I used a hacksaw to cut off the threading from the spindle so I could glue the gear directly to it.
Step 3: Make the Spindle
I drilled some holes in the spindle, and cut the cocktail straws to where they would fit into the peanut butter jar, then inserted (without glue) into the spindle. Nothing inside the jar should contain glue, and more importantly SHOULD NOT CONTAIN SOLDER! A lot of solder contains lead, which is bad, as any self-respecting pirate could tell you. Next, cut a hole in the peanut butter jar lid large enough for the spindle to freely turn, but small enough to help keep it in line. I took the spindles out, added a plastic spacer/washer to the spindle, then the peanut butter jar lid, then the DVD base, and put the cocktail straws back in. I glued the peanut butter jar lid to the base to hold it in place, then once again made sure everything fit. Oh, I also cut the spindle to peanut butter jar depth.
Step 4: Add the Motor
The largest gear that moved along grooves in the disc tray hung out further than the other gears, so I glued the spindle directly to that gear. I also drilled a small hole in the side of the black base and the electric motor casing to tie down the motor and keep it from just spinning on top of the ice cream maker. It would probably be better to actually secure it down, but this worked and I went with it.
Step 5: Something to keep in mind
I gave this a short test and it worked for a few seconds, then stopped turning the spindle. After some CSI work, I discovered the screw holding in the last gear had got glued to the spindle, and caused the gear to become unattached, thus not turning the spindle. I took it apart, and just made sure not to get glue near it the second time. Then I put the spindle back together and tested it again to make sure everything was working smoothly.
Step 6: Prepare the Ice Cream
There are lots of recipes online for making your own ice cream. After a little searching, I went with this instructable:http://www.instructables.com/id/Home-made-Foods-Vanilla-Ice-Cream/
The main reason was because it was for a small amount and would translate well to my project. I mixed in a cup first, then transferred it to the mixer. For illustrative purposes I went with the chocolate mix, and did not use ice/salt like you normally would. I did include ice melt in the pic because I thought it would be something people may already have on hand and use in place of the salt. However, I don't really know off-hand how toxic this would be if it happened to get in your body.
Step 7: Set it... and forget it!
Ala Billy Mays... add the top on to the mixer, and I used a AA rechargeable battery to power the motor. A little electric tape and put the corresponding wires on each end of the battery. The mixer should start turning as you do this. Take the mixer and place in the freezer. I'm not sure how long a battery would power this. At first I was checking it about every 15 minutes to make sure it was still powered and still operational. After the first hour I went to half-hour check-ins. After about four hours in my freezer, the spindle slowed down significantly. I'm not sure if this was a power issue, or because the ice cream was much thicker. I thought it looked ready from the outside, and tore everything apart. In retrospect, it needed to be left in a while longer, maybe with a fresh battery.
See it in action!
Step 8: Enjoy... then refine.
I dipped out quite a bit of the ice cream and then poured out the rest... it clearly wasn't done setting. I still enjoyed it, but it didn't really remind me of ice cream as a kid either. First, I made way too much for just myself. Secondly, it needed to be much thicker, added to the fact that I had never had homemade chocolate ice cream, only vanilla or some fresh fruit variety.
I think this has a lot of potential though... if I had used ice and salt instead of just the freezer, I'm sure it would have set faster and better. The paddles probably also need to be thicker to keep a lot of ice crystals from forming, but it's hard to tell from this batch. Finally, I think I would prefer the vanilla instead of chocolate (a little chocolate syrup really helped the flavoring though).
Overall, this was a pretty satisfying project, and I think the more someone did this, the better results they could get. This project is also entered in the rechargable battery contest, so if you enjoyed it please remember to vote. And, if you guys try this, please drop some pics and let me know how it turned out for you!