Gravity Based

• A gravity-based sorter uses an incline plane to roll coins past openings of various sizes. Begin with the smallest sizes of coin, then proceed to the largest. As the coin rolls by the appropriate hole for its size, it will fall in that hole. There are some physics issues that need to be addressed before sorting in this manner, including the angle of the plane and the material used to make the holes.
  
  

Mechanical

• Mechanical sorters can be made in a variety of ways with different materials. The defining characteristic of mechanical sorters is that the coins are shaken through different-sized holes to separate them. This can be done by creating dividers in a shoebox or stacking plastic containers -- such as cottage cheese containers. The key is to create the right-sized holes to allow smaller coins through while stopping larger ones.
  
  

Tips

• Experiment with different shaped holes. Some have more success with a star shaped hole than a simple round hole. Round holes are harder to size exactly. Differentiating between dimes and pennies in US coins is the most difficult, since they are so similar in size.