The problem is, when I am running a bead on a thin sheet of let's say copper, the edge of the sheet is not always perpendicular to the center of the fence , sometime the edge of the sheet goes under/over the fence (since copper is so thin and flexible ) you remedied it by putting a lip on the fence for the sheet to rest on which is a great solution but what I am planning to do is to either :
A)make the fence wider .or
B)make the height of the whole fence adjustable so it can be fine tuned so the sheet metal edge can always hit the fence in the center.
As you know , sheet metal is not always flat or straight, in my case, copper is often thin and warped/kinked , I'd like to be able to adjust the up and down movement(nod) of the fence so no matter how thin or warped a wide workpiece is, it will always touch the fence somewhere in the middle.