Do you have a Bambu Scraper blade kicking around and want to put it to good use?...., if so then this fully printed safety knife may just be what you need. Even has a printed spring that works perfectly, but still has the option to use a metal pen spring if you would prefer. And a BIG thanks to everyone for printing & feeding back your suggestions (such as a hook loop to hang it up easily) its been a fun model to design. It's one of those functional models I still use daily!!