3D-printed sheet metal louver forming tool. By Proto G Engineering. 3:30 video:
https://www.youtube.com/watch?v=OKj38woOmKI
Previously:
https://www.homemadetools.net/forum/...3231#post77683
https://www.homemadetools.net/forum/...876#post119559
https://www.homemadetools.net/forum/...393#post127208
https://www.homemadetools.net/forum/...724#post143748
