Are you referring to the automatic thread cutter, which has a button to push, or a tiny hook with an even smaller razor blade in it that usually is on the left side of the machine?
The member with the Janome 6600 has only a button to push and all threads are automatically cut..no tails...no wild threads on your clothes, furniture and husband...
I love my 6600 and the main reason is the thread cutter for piecing.
But if you need a convenient manual cutter, I beleive they sell them to stick on the side of your machine. Might be worth a look see. If you are like me, I hate having to pickup and put down scissors. I have put nicks and scratches in my previous machines with my scissors.
Di in TX