When using your walking foot to attach the binding strip to a quilt or to sew many layers, it is a good idea to have both legs of the walking foot on the fabric.
Notice in the above image that the foot is in line with the edge of the fabric. So both legs are on the fabric. This will help bring the fabric layers forward in an even way. Only problem is the needle will hit the fabric quite far from the raw edge making your seam allowance abundant!
There is a simple solution. Leave your foot where it is and move your needle to the right until you have an acceptable seam allowance. (see photo above).
Many of the newer machines have the option of moving the needle to the right.