Modular Shelf Connectors for Dowels or Rods

I bought a shelf system from Amazon a few years ago, and I thought, "I could 3D print these and use wooden dowels". So I recreated the connectors and made them fit my needs better. They print in two identical parts and connect with a simple "Dovetail" wedge. The dowels need to be 3/4 inch, but you could scale them down or up if you have the space on your print bed. The completed length is just over 19.5 inches. Adding a sheet of thick cardboard or thin hardboard will make the shelf easier to use, or you could copy the original product and sew two sleeves on a piece of fabric to slide tightly over the outer rods. I'll probably add a few different versions and connectors to fit more needs, like flat backed connectors with a place to screw in a backboard, or a narrower design to fit in tight spaces (and print in one part).

I just added a second version that uses a 3 crossbar design, with the middle bar acting as a locking pin for the wedge. This cuts down material cost and removes the need for glue. The socket on v2 is for a half inch wooden dowel, because those are cheaper in stores near me, but you could also use 0.25 inch Schedule 21 or 40 PVC pipe. 

~Fun Tip: Use the diagonal of your print bed and the Pythagorean theorem to maximize the length of the parts in order to get the most out of a smaller bed size.