You will need:
- A pen (less weight,the better)
- A strong magnet: For the greatest gap use two neodymium magnets.
- Some string
- Some tape
- Tape or tie the string to the pen.
- Tape the magnet to the top of the pen.
- Attach the top magnet to a hanging surface with either tape or by using a metal surface
- Carefully let the pen magnet closer to the hanging surface while keeping tension on the string.
- When the maximum gap is obtained that still supports the weight of the pen is achieved, tape the string to the surface.
That's it! Enjoy!