15x15x10cm you do not need a soldering iron.
Build your own marble machine.
Http goo gl yjd1bn my other projects.
If you can get it to the top gravity will do the rest.
Think about how you can design your own lifters and get your own ball rolling.
Switch battery aa with battery holder screws pack screwdriver.
Build your own marble machine and feel it.
Laser cut wood components motor with rudder arm steel balls.
Sandpaper knife wood glue.
Place the cut out trash parts between the ball track and use it as the strut.
Take a sheet of paper and draw out some ideas.
Take a look at these awesome videos to get a few great ideas for lifting the balls of your own marble machine.
A marble machine is a creative ball run contraption made from familiar materials designed to send a rolling marble through tubes and funnels across tracks and bumpers and into a catch at the end.
For simplicity the wires are terminated with pins.
Engraved dotes and squares on the strut and holes in the couplers defines which coupler where should be glued.
Then glue all the couplers in the proper slots.