In order to utilize any size/shape of photo in the wall, I needed to be able to consistently punch the holes for the connectors. This small tool allows for easy and consistent layout.
This allows you to utilize any size of photo in the matrix. My main use case is 5x7 inches and a few 4x6 inch sets.
Push a nail or other sharp tool through the thicker side for alignment, through the photo, and out the other size. It works best if you punch through from the back, since you'll be pushing the connector rods up through in that same direction.
Original OnShape model link if modification is desired: https://cad.onshape.com/documents/15c07f5a27ea66770d062dd8/w/ae98a127d4ef71b9559ec0a1/e/0a50226f4d3d117a3fc5a371
The author remixed this model.
Stand alone corner hole punch to allow for any size photo to be used