These are all of the supplies. You will need:
1 Wooden Block
A Stick of plastic tubing, VERY THIN!
2 Same sized small marbles
1 Bottle of Wood Glue
1 Paper Clip
1 Scissors to cut the tubing
Step 1: Marble Machine Tutorial Step 1
Step 2: Marble Machine Tutorial Step 2
The second picture is what the machine should now look like the one in the picture.
Step 3: Marble Machine Tutorial Step 3
An optional, fourth step would be to make the marble go off the tracks and back to the beginning using a lift. Since I'm doing that right now, I'll be uploading a tutorial soon. But, don't worry... I'm sure you're smart enough to figure it out yourselves.