I created a shelf pin jig. My drill bits are the type that are used in regular store-bought jigs with a 10mm insert (can be for 5mm or ¼", but the holes on ends for indexing are for 5mm- can be drilled out for ¼"). 32mm spacing and 32mm from each edge (for inside edges and using the fence part for outside edges). The 2 end holes can be used for indexing. 

I printed with 3 perimeters and in PETG.