Allright folks, gather 'round!
I have for a while searched the web for genuine and simple information, such as calculation on hole sizing, spacing and so on. Finally i found this PDF:
http://www.koolbamboo.com/FluteNotes.pdf about bamboo flutes. This compendium gives you what you need to have your questions answered.
When it comes to tuning you have to measure the inner diameter of the bamboo cane (mine was 15 mm), then you multiplicare this measure with 23 to get the total length of the flute. This also determines what key your flute will be and is described in the compendium.
Measure from the middle of the soundhole's position and cut it a litte over your disired length. I found out that my flute was going to be 345 mm so I cut it at 450 just to be able to trim it if nessecary.
You now have your flute "in the raw" and you should drill your soundhole/blowhole. This should be 2/3 of the inner diameter. So again, mine was 15 mm, so the soundhole should be 10 mm. Then if you take a look at chapter 6 in the compendium it explains the tuning. Remember to always have the middle of the soundhole as your starting measure point. Then you place the first hole 43% down the flute, the second at 50%, the third at 58%, fourth at 68%, fifth at 73% and sixth at 83%. This is very well shown in the compendium. If this percent thin is hard toger a hold of just imagine the example flute to be 100 mm instead of 100%. Then your first soundhole should be 43 mm down the flute, the second 50 mm and so on.
I drilled the fingerholes gently with a 5 mm drill and the expanded them carefully with a round file. I guess that it's better to heat up a proper iron and burn the holes to disired size because it is easy to split or damage the wood when you drill.
When it comes to the actual tuning, note by note, I have a very good ear but for the fine tuning I used a regular guitar tuner. So I started with the keynote and worked my way up a major scale.
See if this photo link works:
https://lh4.googleusercontent.com/-xNWmNUMK1dg/Tnw2pQe-FqI/AAAAAAAAByQ/U15QJVljgA8/s720/Sideblown.JPG
