The things I used for this are easy to get, the main piece is a clock motor, I used the most common clock motor there is, almost all clocks have it(A square black one saying QUARTZ) You probably already have multiple of these in your house.
In the next steps I'll explain how to build this. If you start building it, keep in mind that you need to make the rotating parts move smoothly over eachother, because these clock motors are build to rotate very light pointers, they do not have a lot of power. If the parts can't slide smoothly over eachother the mechanism will stop.
edit: user 'talty' commented below that it is uncertain if it's harmful to let polymer clay get in contact with food! So I recommend that if you use polymer clay, add a layer of harmless varnish(I don't know if that exists). You can also make the feed segments out of river clay, or completely out of wood.
edit #2: The cat feeder I made seems to stagnate sometimes, this is because the disc is too heavy for the motor. You don't want it to suddenly stop when you're gone, so make the disc as light as possible! I made a new disc out of a thin sheet of plastic, it works better. You can also look for a stronger clock motor, like this one.
edit #3: user 'spencerawr' had the idea that you could also make a small version of this, hang it upside down above the aquarium and use it as a fish feeder.
Step 1: What You Need
- clay(I used FIMO, which is a polymer clay and those are expensive if you use a lot. If you can get a cheaper clay that works fine aswell, use that) and an oven to bake the clay
- thin wood. This is for the cap on top, for the disc, and for a little block under the clock motor.
- from a clock: the motor, the second pointer, and the hour pointer
- a wide round cookie can you don't use anymore
- two nails
- cutting pliers
Step 2: Getting the Motor
2: On the back was this motor. Almost all clocks have these, except the small clocks where they don't fit in.
3: Get the motor out of it, DON'T THROW AWAY THE SECOND POINTER AND HOUR POINTER! But you can throw away the rest.
4: This is how it looks on front. There are two white tubes in the middle around eachother, those are for the hour- and minute pointers, the pin in them is for the second pointer.
Step 3: The Lowest Part With the Segments
2: Draw a line all around it on about 3.5 cm from the bottom.
3: cut the above part off. You can do this with a cutting pliers.
4: make a layer of clay on the side of it, and make it round on top. Try to make it flat, so the whole side on one height. Then bake it. You can later paint this side.
5: Get a piece of wood of about the size of the clock motor. If you lie the motor on top of it on the middle of the can, the black part of the motor should be below the sides of the can. But not too far below, best is about 1 mm, so the white thing in the middle is higher than the sides. This piece of wood is actually just to save clay.
6: Now make this with clay. Take the color of clay you want it to be in the end, because you shouldn't paint this part as else your cat could eat the paint, unless you have real good paint. Also, with clay you can just wash it out with water. I made the motor holder in the middle square-shaped on bottom, so the shape of the motor, and round on top, so the shape of the disc.
7: Fit in the motor. If it doesn't fit, you can vile the corners a bit out with a dremel, and you can later soften it with a polish bit. You can best use a polish bit on all of the clay, to make it smooth, that looks better. You probably had some fingerprints in it somewhere, you can wash them away.
Step 4: The Disc
2: Bend it in half and put tape around it. This makes it stronger but it needed to be shortened anyway. If you hour pointer is still too long you can cut a part off.
3: Mount it to the motor. Also, make things on the sides that can hold the motor in place(Don't glue the motor to the clay, because later you may want to replace the battery) I used metal wires, they are inserted in a hole in the clay. Actually I used too big wire, you should use a thinner, more bendable type. This may work better with thin metal strips, if you have those.
4: Bended inside.
5: Make this disc out of thin wood. There should be a hole in the middle that fits around the white thing on the motor. Also cut a quarter out, till the motor part, you can best leave that covered.
6: Take two nails and smash them into the wood near the hole, so that on the other side the hour pointer fit between them. You can best make the heads as flat as possible, to make the surface flat. You can vile them flatter with a Dremel, and also smash them in some deeper by holding something sharp between the nail head and the hammer.
7: So you have this.
8: Cut the nails off so they dont touch the motor,but leave them as long as possible.
9: Put the disc on the cat feeder, with the nails around the hour pointer.
Step 5: The Cap
2: Cut the sides of the second pointer off.
3: Make a cap from wood about this size.
4: Put the second pointer upside down on it. I had to make a little pit in the middle of the wood with a drill to make it fit.
5: Connect it to the wood. I did it in a very unproffesional way, but it's effective. You can do it differently if you like.
6: Mount it back to the second pin. It should again tick.
2: I glued an instructions manual(handleiding) on bottom because I'm giving this as a present.
3: And four mats so it stands more stabile and the bottom keeps clean.