1. Build the base.
Stand the 3"× 1½" PVC coupling on its wide end,
and insert the 1½"× 1¼" bushing. Cut a length
of 1¼" PVC pipe about 2" long and insert it
into the bushing. Don’t jam the parts together.
Press-fit them just enough that they’re joined,
but loose enough to disassemble.
Connect the tee to the 2" length of pipe
2. Prepare the motor.
Wrap the motor in electrical tape so that it fits
snugly inside the 1" side outlet of the tee.
To create the bottom roller, first wrap the
motor shaft in tape until it reaches about ½"
in diameter. Then split a length of electrical
tape in half, lengthwise, and wrap the split tape
around the middle of the roller (Figure B). This
“crowned pulley” shape will help the rubber
belt stay centered on the roller (see MAKE
Volume 22, “Puzzle of the Crowned Pulleys”).
3. Make the collector.
After enjoying a 12oz aluminum can of your
favorite beverage, rinse and dry the can.
Remove the top with a can opener (Figure C).
Be careful of the sharp edge inside.
PVC pipe coupling, 3"× 1½"
These can be hard to find; you can substitute
one 3"× 2" and one 2"× 1½".
PVC bushing, 1½"× 1¼"
PVC coupling, 1¼"
PVC tee, 1¼"× 1¼"× 1"
PVC pipe, 1¼", about an 18" length
DC motor, small, between 3V and 9V such as
Jameco QJT-260-18130, jameco.com
9V battery snap connector such as Jameco 216452
4xAA battery pack with 9V connector snaps
like Mouser 534-2476, mouser.com
Batteries, AA ( 4)
Wooden dowel, about 1" diameter or wooden/
Glass fuse, about 1¼" long and ¼" in diameter
Stranded wire, thick 14 gauge or 2.08 sq. mm
Soda can, aluminum, 12oz
Knife or scissors
Pliers ( 2)
Handsaw to cut PVC pipe
Drill and drill bits
Hot glue gun and glue
Soldering iron and solder
4. Prepare the top roller.
To take the ends off a glass fuse, use a candle
and 2 pliers. Grip one end of the fuse with one
pair of pliers, holding its other end over the
flame. Use the second pair of pliers to remove
the hot end cap (Figure D), being careful not
to touch the hot glass or solder. Repeat for
the other end of the fuse.
Remove any wire inside the fuse with the
pliers. If there’s soot on the glass tube, clean
it with rubbing alcohol and a cotton swab.
From now on, try to keep the fuse dry and free
of oils from your hand.
5. Make the top assembly.
The top assembly consists of a short length
of PVC pipe underneath the can; inside the
pipe is the glass top roller, mounted on a
wooden dowel. The top brush enters through
a hole across from the dowel, and its other C
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