Rebar safety cap

In my garden I have some long rebar that are I attach trellis to. Now that my kids are walking I worry about them falling into them. I wanted the standard orange caps you see at construction sites but all I could find at the big box store were 4" square overkill things that still had sharp corners and cost $4 each. So I printed these.

My rebar is #4 (1/2" diameter) but in reality they vary quite a bit and some have elongated seams along one direction. So I made the opening a 9/16" x 3/4" oval