The Limit stamp (lim)

thingiverse

When I was taking a calculus class my junior year here at UNH, my professor, an amazing teacher and tutor, mentioned her long-held desire for someone to create a limit stamp for her. I had forgotten about her request until I came to her with another prop idea for the 3D printing prop assignment. Without fully articulating my idea, she interrupted me and said, "Please tell me you're making my limit stamp." It was decided: the prop assignment for me would be the limit stamp. So, what is a limit in calculus? You ask. According to Khan Academy, a limit describes how a function behaves near a point. The limit stamp features a rotating base that allows for three different sizes of the phrase 'lim'. A rod attached to this rotating triangle enables movement between the stamp's sides. Magnets were included in the design and print to allow each stamp face to maintain a fixed state while in use. The stamp material used was not PLA but TPU, printed separately. The print was divided into four parts: 1) Base body with magnet, 2) dowel with magnets, 3) triangle for stamp, and 4) three stamp faces. For the fourth part, the stamp faces were printed using TPU rather than PLA. 1)Base Body Print: Time: 7 hours, 2 minutes Type: PLA Amount: 95 grams Support: Yes, needed 2)Dowel with Magnets (3 magnets): Time: 17 minutes Type: PLA Support: No During print, pause at layer 12 to insert 3 magnets. Super glue may be necessary to secure the magnets in place. 3)Triangle Stamp: Time: 59 minutes Type: PLA Support: Yes 4)Stamp Faces: Time: 2 minutes per face Type: TPU Additional settings were altered, including slower print speed and lower bed heating. Support: No Details on how I created each part can be found on my blog at http://3dprinting.illustratingmath.com/2019/12/11/the-limit-stamp-prop/.