In fact you may have to break up the last to fit a full lize last into your 3D printers build envelope.
Not many machines are large enough to 3D print a pair of shoe lasts at the same time anyhow. I don’t recommend that you print two lasts at one time. Now that you have your last file you should break it up so you have one side. Shoe lasts don’t resize or “ Grade” in a linear fashion. Really tricky if you need to make a size change. It will take some time to get the last modeled.
Most CAD programs will allow you to make a surface Mesh from the. stl files, so if you need a size other that US 9 you maybe in for some CAD work. You can download our sneaker last file Here or you can search Thingverse or you can check out CRABCAD. STl or other CAD file to print a shoe last. Learn How to 3D Print a Shoe Last: 4 easy steps Download a last file