A simple design by Matticus Finch, which I recreated and remixed so it is fully printable and can be assembled in a few seconds. You could scale the connecting rod for wider or narrower stands, and also adjust it in the other two axes to get the right friction fit. The tolerance is 0.3 mm. EDIT: other version with 0.1 mm tolerance added
Printing:
Orient the two sides so that the hexagonal cutouts are on top. Use at least 3 walls.
The connecting rods are designed to be printed on their sides for maximum strength. Ensure to use at least 3 walls and 5 top and bottom layers.
The author remixed this model.
providing .step , hexagonal cutouts and hexagonal connecting rods