A brainy junkbot with a downspout body.

Step 1: Parts and Tools:

Parts:
One round downspout piece (Home Depot, gutter aisle).
One wire strainer (Home Depot, gutter aisle).
Two 1/2" conduit connectors (Home Depot, conduit aisle).
One braided toilet supply line (Home Depot, toilet repair aisle).
Two battery charging clips (hardware stores other than Home Depot).
Two 3/16" axel hat nuts (Home Depot, screw aisle).
Two #10 brass finishing washers (Home Depot, screw aisle).
Four #8 x 1/2" sheet metal screws (Home Depot, screw aisle).
Two #8 x 5/8" machine screws (Home Depot, screw aisle).
Some circuit board scrap that you got by smashing something.
Some foamboard.
If you want your junkbot to hold a sign: a wire stake (Home Depot, sprinkler aisle) and possibly a thin metal shingle (Home Depot, roof aisle).
If your want your junkbot to be painted and have decals: spray paint and decals.

Tools:
Wire cutter
Dremel with cutting wheel
Phillips screwdriver
Hot glue or metal epoxy
1/8" drill bit for metal
1/4" (or near that size) drill bit for metal
Tin snips (if you want your bot to hold a sign)

Step 2: Make the Legs

Cut two 3" pieces of the supply line and drill a 1/8" inch hole near the end of each one. Drill a 1/8" hole on opposite sides of the downspout, near the bottom. Use the Dremel cutting wheel to notch the downspout where the holes will be to prevent the drill bit from wandering. Attach the legs to the body using the 1/2" sheet metal screws.

Step 3: Add the Feet

Slide the conduit connectors over the supply line to make the feet. Screw the 5/8" machine screws into the back of the feet to hold them in place on the legs. To make sure the legs stay centered in the feet, put a little washer or other spacer on the front side of the foot.

Step 4: Add the Arms

Wrap a piece of wire under the small screw at the end of the charging clip and loop the end of the wire for a sheet metal screw to pass through. Drill 1/8" holes on each side of the body, above the legs, and screw in the arms using the 1/2" sheet metal screws.

Step 5: Make the Brain

Clip the wires off the bottom of the metal strainer and cut a piece of foamboard to fit snuggly in the bottom. Cut some pieces of circuit board to fit within the strainer, and cut slits in the foam board for the circuit board pieces to sit in. If you're going to paint your bot, paint the top of the foamboard the same color before inserting the circuit boards. The assembled brain in the photo has reflective silver mylar on top of the foamboard. Secure the circuit boards in the foamboard with a little glue. Secure the brain in the body with a little hot glue or epoxy.

Step 6: Make the Eyes and Mouth

To make the eyes, hot glue or epoxy the axel hat nuts into the finishing washers and hot glue or epoxy the assembled eyes onto the body. Drill a 1/4" hole in the body for the mouth and the basic bot is finished.

Step 7: Add a Sign

If you want your bot to hold a sign, cut a piece of the wire stake and hot glue or epoxy a message to it. To make the message, you can cut a piece of the thin metal shingle and paint on it or put a sticker on it, or cut something out of a metal food container.