I designed this end cap to add support in my kitchen's lazy susan. I used a 30cm long aluminum rod with a 10mm diameter and printed two caps for either side. The inner diameter of this cap is 10.925mm, the outer "foot" is 40mm. Very simple STL that should be easy to edit and print for all kinds of sizes and projects.

I put a channel in the bottom of the foot for glue if desired. It doesn't affect the model (though it does seem to improve printing).

Just print it - it's very simple. There's a channel at the bottom of the print to apply a bead of glue, if desired.