I have a tent that I'm happy with but the pole sections are 24" long. I found tension pins at the hardware store today that were the perfect size for my project.
I needed 1/4" X 2" for my poles.
I took a screwdriver and widened the gap in the tension pin. Drill a hole in but not through a block wood to hold the pin for you.
With one end widened it's a tight fit putting in inside the pole. The other end remains small enough for the pole to slip over like it's intended to.
Once I run the shock cord through I'll have cut my poles down to about 14" making it more compact for packing.
* BONUS TIP *
Since there is a split in the tension pin you can just stretch the shock cord thin enough to snap into the pin tube! When cutting down the aluminum rod just be careful not to go crazy and cut the cord...No need to fish new cord through a tiny tube!
Finished product packs down to 6.5" X 15".