I made these to fit a ¼ (.25) inch dowel rod from the hardware store that can be picked up for $1.25 in lengths of 4 feet. Holes were made to size, but it takes the rods snugly when printed at .2mm layer heights. Edges are nicely chamfered, and it prints easily and quick. You could scale these parts to fit different dowel rod sizes if you wanted to. I included little holes in the side in case you wanted to drill through the rod and pin it in place, though I'm sure glue would work as well.
I saw various models that functioned similarly, but never for all the pieces that I needed in the same sizes. I used these to build a rudimentary box to give structure to a cloth storage container that would collapse on itself on my baby changing table caddy. I saw someone else making a kite with something similar to these, and I plan on making a down and dirty enclosure for the printer in the near future.
The author marked this model as their own original creation.