One of the activities of our team is the teaching and development of experiments for STEM education in [ Uni for kids ]( http://uni4kids.bg/ ). And one such experiment was an experiment visualizing how the hadron collider works and how the solenoid works. So, as a result, we have that:  But for the development of this experiment, we need a roll bender. Unfortunately, there is really hard to find a small one and a cheap one, so after some googling we find [this](https://www.wcwelding.com/rod-roller.html) and later [this one](https://www.thingiverse.com/thing:835165) And after some designing and development, we develop own version of this tool that is robust and 3d-printable. ### Materials and methods #### Print-settings: The Model is fully optimized for 3d printing - Support/rafts: none (if you are not sure in your printer, you can add touching build plate support) - Layer height: 0.2 - Material: PLA - Shell line count: 3 /for rollers 5 #### BOM - 4x bolts M8x55mm (for passive rollers and top mount) - 2x bolts M8x35mm (for handle) - 1x bolt M8x85 (for active roller axis) - 1x anchor bolt (for the slider, this bolt must be filed as shown on images and glued in knob and ball inside the slider) - 1x bolt M8x100mm with rectangular slot (for lever handle) - 4x 608 ball bearings - 8x nuts M8 - one piece 10mmx80mm aluminum tube (for lever handle) - a tap for threads - mood for needlework