I printed the original whistle in ABS and found out that it was nigh impossible to knock the little ball loose. So, I made a version without it. But I wanted the trill the ball adds to the whistle, so I managed to work out how to make it way easier to knock loose. For me, a tiny tap broke it loose.Print with no supports (duh), no raft, no fill, and 3 - 4 shells. If you used the version with a ball, just knock it loose with a flat object when it's done printing.