How to make a coin cannon?

1. Required parts

* A barrel (close to the inner diameter of the coin
* A flat surface (a small plank)
* A large rubber band
* 2 smaller rubber band (or more for more stability)
* 2 nails
* Tape
* A large torus shaped item for the trigger (blue on image)
* A rope
* Some coins

2. Making the gun

The idea is that we try to make a sling with a barrel. 1. First we insert the 2 nails int the plank and insert the barrel in the middle in such a way so there is no space left between the nails and the barrel.
2. Fix the barrel to the plank using tape.
3. Wrap the smaller rubber bands around the tapes and the nails.
4. Tape the larger rubber band to the torus shaped trigger and attach the rubber band to the nails.
5. Lower the normal state of the larger rubber band by wrapping the rope to the large rubber band and the plank.
6. Done.