Making a PVC flute is probably easier to do than describe. If you have a bamboo flute to use as a model, then I recommend you start with that. I prefer to use Schedule 40, one-inch diameter pipe. I use an electric drill on very low speed, so I don't melt the plastic. Start by cutting the pipe a bit longer than you think you will need. You can tune higher by cutting but you can't easily lengthen it to lower the pitch. Plug the mouth end of the pipe with a PVC end cap or a champaign cork. Then drill the mouthpiece, so you have a way of sounding the fundamental in order to tune it. The mouthpiece works best when oval shaped, with a sharp edge on the far side of your mouth. Make the oval by drilling at angles and widening sideways. Then tune the fundamental tone by shaving slivers from the bottom with a hack saw. Start drilling finger holes with smaller bits, from the low hole upward. Estimate the positions first with math (calculating divisions) or by comparing to other flutes of similar length and bore diameter. Start the holes a bit farther down than you think you will need, and widen with larger bits to raise the pitch until the pitch comes close to what you need. The diameter of open lower holes will affect the pitch of upper holes, so you want to get each hole as close as possible before starting the next higher pitch. That's it in a nutshell. - Robert