To DIY it, get a suitable aluminium rod, and a 1" thick rectangle of wood, MDF, or plywood, of about two inches longer than the rod.

Cut a dado into the middle area of the wood, the same width/depth as the thickness of the rod. Centre the rod into the dado (slot), and hot-melt glue it in place along the sides of the slot. Glue wooden blocks (plugs) into the ends of the slot to completely secure the rod.

Let the glue(s) harden fully.

Now chuck up a 0.10" thin-kerf carbide-tipped blade in the tablesaw. Flip the assembly face down on the saw, and cut a slot into the rod using repeated passes with increasing kerf depth. When done, break or saw the assembly apart to retrieve the finished rod.

If you don't already have the gear, it may be better to take it to a machine shop.

Cheers

-ml