This is a 45 degree drilling jig that I knocked up for making holes through corners. This makes the process of installing dowels in box corners much easier.
In practice it could be a bit longer as the clamp can get in the way. I also removed the part of th e metal band that is bent around the corner.
GREAT idea! I was looking for a way to drill hundreds of holes in a vertical support stud to suspend cantilevered shelves from using 3/8″ hardwood dowels and your design is very close to what I need – I am just going to add sides to be able to firmly clamp the jig to the the work piece to secure it while drilling.