A round baseplate for a Bosch trim router to replace the rectangular one. Much more useful for routing with a straightedge as a guide since the distance to the bit doesn't change with orientation. Put the center jig in the collet and use it to center the baseplate to ensure that the baseplate is centered on the centerline of the bit. The cutout in the baseplate is for the Bosch accessory fence. Print the centering jig with the shank end up for no support printing.