Fig. shows an image of the 45° beam-splitter mount. The mount consists of a 7.5 mm-thick 3D-printed plate with three angled mounting holes, a central 1" hole to pass the incident light beam, and a 1 mm-deep, 26 mm × 26 mm recess in the front face to support the beam-splitter. The beam splitter is made by cutting a 25-mm section from the end of a 25 mmwide glass microscope slide, forming a square that can be glued into the mount using epoxy resin or other suitable space-filling glue.