I've got a closet in my spare bedroom (storage room) that I wanted to add another clothes hanger rod to. Among my scrap pieces I had two 1.25" diameter closet rod sections that together would be long enough, but neither was long enough on their own. The distance to span was roughly 22".
This is a CNC-cut splice joint I came up with to solve the problem. My test cut done on smaller scraps is shown in the photos. I'm calling it my radial finger joint.
The finished spliced rod is now loaded with clothes and is handling the weight with no complaint.
To hold the dowels on my CNC I used my adjustable angle clamping jig set to vertical with a vertical scrap of plywood clamped to it. The dowels were trapped/clamped against the jig and edge.
4D
