My first marble machine

Marble machines are one of the best ways I know of for experimenting with mechanisms such as levers, pulleys, inclined planes, gears, or cams. The one in the following video is the first one I've built:

But let's start from the beginning. During last year's Maker faire I got surprised by the skills of Denha sensei at building his own complex marble machines.

After the Maker Faire, I spent hours admiring his creations and how he checks every detail in a methodical way. I came to the conclusion that a marble machine is usually made of some of the following components:

• Fences for balls not to escape
• Ball accelerator (inclined plane)
• Lateral motion
• Flip-flop
• Funnels
  • One step (can be made with wood spoons)
  • Funnel laddles
• Ball release mechanisms
  • Ball stopper with weight attached
  • Ball passing gives way to waiting ball
• Lifter/Elevator
  • One-stage lifter
  • Two-stage lifter (linkage)
  • TJ (Theo Jansen) lifter
  • Swinging arm lifter
  • Arm lifter
  • Spiral
  • Wheel
  • Zig zag lifter
  • Cardan lifter
  • Stairs lifter
  • Rotation lifter
  • Elevator
  • Push up lifter
  • Catapult
  • Double wheel lifter
  • Rolling ball lifter

For my first marble machine I tried to make it simple. For that reason, I only used two common artifacts: a wheel elevator and an inclined plane. For finding the centre of the wheel, I used simple geometry. However, I had to drill a big hole for the bearing to fit in. That affected the accuracy of the centre. For that reason, I had to use a small spring that would automatically adjust the distance between the wheel and the motor's shaft (probably it would have been easier if I had used brass wire for the wheel's axis instead of a bearing). The inclined plane was made using a chisel. This is the list of materials I used:

• Geared motor: MOT114A1B 6V 60RPM 12GA (Sengoku 1280yen)
• Gear for the shaft of the motor (Sengoku) and a rubber cover (Ishikawa-neji)
• Balls 7mm diameter (Tokyu hands)
• A small spring (from a pen)
• Brass wire 1mm diameter (Radio depaato in Akiba)
• Wood (a home center and Daiso)
• On/Off push switch (from an junk board)
• 2*AA batteries with a case (Daiso and Akizuki denshi)
• Aluminium plate (Yokyu hands)
• Bearing (from an broken stepper motor)

This is a list of tools I used:

• A precision hand drill
• A precision wood saw
• Dremel 4000 with various bits
• Tweezers
• Cable cutter
• Long/round nose pliers
• Tape
• A universal vise
• Chisels
• Sand paper

Conclusions: I failed many times, but I also learned a lot during the process of building my own marble machine. Indeed it was harder than what I had expected. I will try to build upon these lessons learned, and make a better marble machine next time. You can check my notes for more details.