Autochange for two voices

[Justin]

Hello,

I am trying to typeset scales for two hands on the piano like so : 
http://postimg.org/image/bq0hqyv1z/

I was able to get to this point: http://postimg.org/image/qfsrmlo85/

but I can't seem to find a way to disconnect the upper voice from the 
lower voice. I am using \autochange which I believe might be the cause 
of the issue.

Does anyone know how to properly format the music? 

Here is my current code (short version): http://pastebin.com/FAyGj0z4