You can buy bamboo or use a bamboo fishing reel to cut your flute body. Cut a piece of bamboo between 18 and 20 inches. The diameter should be about 3/4 inch. There is a fiber wall between the sections of bamboo. Cut your bamboo so that one end of the bamboo has the block and the other end does not.
Use a marker to place hole indications along your length of bamboo. The first hole an inch from the blocked end of your bamboo piece. Measure 6 inches from that mark and mark six hole positions 1 inch apart, giving you a total of seven holes.
Heat your steel rod over a fire, use a heavy cloth to hold it and slide it through the opposite end of the bamboo where you placed your first hole. Press the steel bar in bamboo to burn off the fiber stop you do not need. The blockage at the end where you placed your first hole should remain.
Heat your drill. Use a pair of screws to retrieve the hot drill and burn the holes through your markings. You can use a drill, but you risk cracking bamboo. A very hot drill can easily burn out the holes in your bamboo flute.
Roll your sandpaper to fit into the holes you have burned and twist it several times to remove the black bamboo and smooth the perimeter of the holes. You can also widen the holes a bit, making it easier for you to get sound. Be careful not to go too wide, or you will have trouble covering the holes.
Tips and warnings
Flutes are musical instruments in the wind family. Over the years, flutes have been constructed of various materials, including ceramics, metal and wood. One of the simplest materials for making a flute is bamboo. Building a bamboo flute takes very little effort and a few simple tools. Learn how to take a piece of bamboo and turn it into a musical instrument that you can enjoy playing for years.