[JesseK]

Yes, I used a variable-speed drill and a file that has 4 different surfaces to file them down. They're not perfect, but to file 10 of them it took ~45 minutes.

To drill through the metal pieces it took 10 minutes since I came up with a way to do them all at once.

I bent the metal by hand so it's not exactly 45 degree, and the spacing on the rollers isn't exact either. It's a concept though, to show that it can be done.