newbie! - help with trying to sew 4 layers of fabric together.

I have a Bernina Artista 630e  - I don't think this really matters but that is where i'm coming from.

ok, so what I have is first

1 layer of cotton print
then 2 layers of fireproof batting
then another layer of cotton print

the problem I'm having is no mater how careful I am,the top layer always starts to bunch up and skews off center, the other layers are fine, the lower the layers the better they are.

How do I keep the top layer from bunching up and shifting?  do I need a .. can't remember the exact name but ... a presser foot with dog feet in them.. do I need one of these?

thanks
Brian S

Yep- that foot is called a walking foot. When you have multiple layers like you do, the bottom layers are being moved along by the feed dogs, but the top layer is just slipping by. This is how your layers get messed up.
A walking foot will move that top layer of fabric in time with your feed dogs therefore keeping all layers together and in sync.
A walking foot for a Bernina can be a little expensive, but will be well worth it if you plan on sewing layers often.

I agree with Irene a walking foot is the best investment ever.  I just got a new sewing machine and I love my walking foot, it makes sewing layers very easy or at least way easier.

The walking foot will definitely help, but also, try lengthening your stitch length--since there's more thickness to go through, a short stich length is really going to get pulled to a tiny little bit of nothing and muck everything with the shifting around.

On some sewing machines you can also lower the feed dogs so that the bottom layer wouldn't be feeding through faster than the top.  Might be worth a try (with some scraps) if you don't want to shell out for the walker foot just yet.