Roller bender. By Skillful Hands. 7:25 video:
https://www.youtube.com/watch?v=jbEUcg2OX00
Previously:
https://www.homemadetools.net/forum/...454#post162180
https://www.homemadetools.net/forum/...214#post161310
https://www.homemadetools.net/forum/...236#post154019
https://www.homemadetools.net/forum/...055#post140976
https://www.homemadetools.net/forum/...822#post137091