This is a simple rod spacer to maintain a constant distance between two rods.

I made this for my clothes drying rack to avoid falling down because my vacuum robot will push one rod to the other.

The design is half of the object, you will need to print two of them and glue them together.

The design is fully parametric but as I was too lazy to do this with OpenSCAD (that is not very handy with fillets), it is under Fusion360. The Fusion360 source is available in the downloads, you just need to open Modify / Change parameters and adapt the rod diameter and the length to your need.

The STL file is for rod with a diameter of 16mm, and 14cm long (28cm with the two half), and a width of 2cm. You may also simply scale the item to your rod diameter, or let me a comment with the size you need and I may publish it if I have some time to do this.

I use it with some stop items (https://www.thingiverse.com/thing:4126819)