I bought a hacker A50 16L for wind s 110. When I received the motor I found it is a little from the old v2 type. The laser mark on the motor is v2.1, and the shaft is no longer 6mm. It is 6mm at the top and 8 mm on the other end. Look at my pictures. The problem is I bought spare shfts from hacker and they are still 6mm. What happened?

Looks like you got the first of a new series motor. Send aero-model or Hacker an email and let them know what happened; they'll make it right for you.