Airfoil converted?

[bowns]

It's found that most blades using either airfoil 0012 or 8H12 typically.But i happened to compared them with the ORIGINAL data and prints and noticed
they didn't match exactly.Why this and,does it matter?
Can any one help me out?

[Doug Riley]

8H12 (a cambered airfoil) is common on gyros; 0012 (a symmetrical airfoil) is uncommon on gyros.

Many people build cambered blades with a perfectly flat bottom. This is probably because it is easier to build them this way (especially in wood). The true 8H12 is not flat on the bottom, however. Those blades that have an accurate 8H12 will perform better than the flat-bottomed ones.