I have some experience using 3D printed parts for bending tubes. I have made purpose-built dies to bend shaped tubing (shown below) and I am working on an FDM 3D printed/laser cut steel, heavily Cobra-and-mattthemaker-inspired bender that will allow me to bend CS and SS material in tandem. I’ll post pics of this when it is finished, hopefully in a few days.
I needed to bend a tapered CS at one point, so I made the following 3D printed “dies” that were sandwiched in steel plates and squashed in a vise. This worked for the single small bend I was trying to achieve, but would likely not work for any larger bends or too many more bends, as the forces seen at the ends of the die are large compared to the resilience of PLA. I made the CAD designs in Solidworks, I sliced the .stl’s in PrusaSlicer to have 6 vertical shells and a triangle infill (the strongest shape IMO) of 80%, and I printed the parts on my older Creality Ender 3 with black 1.75mm eSUN PLA+.
*New users of the forum can only upload one media item per post, so please excuse my bicycle-pubes-level photoshop collage.
This process *works* in situations like this where little else will, but I don’t recommend it outside of one-offs.