Step 3: Model the tooth from that single poly. Cut it, extrude, do what you like, but don't change its borders.


Step 4: Now you have to copy the tooth. Use shift + Rotate or Array. Anyway, you need to make a precise turn. In this case I made a 10 degrees turn and then created 35 copies of the tooth.

Step 5: Voila. Now just attach all teeth to the main object, weld the verticles, and you are done

Legs

Here my design skills failed, I had lots of ideas but couldn't find the proper one for a long time. I thought about 6 buggy style wheeles, but it made the toaster look like roller-skate. Tank tracks made it much too low. Then I tried mech-like legs. I loved the idea, but it wasn't easy to make. You can see one of failed designs here.

Details

As I said before, details make a scene more interesting. Here you can see some of them: the screws and bolts, for which I used Wikipedia as a reference and some wires, which are simple splines converted to polys and beveled. Those twisted small wires were fun to make. First I drew 3 wavey and smooth splines, then I put on them the Twist modifier and finally some FFD. The leg and arm joints (arm joint on this screen) are spheres and cylinders with a lot of beveling and extruding, and a bit of chamfering.