The Process
Scan object
The process of photogrammetry uses a set of photographs to reconstruct the shape of an object. For detailed objects, high resolution photographs are required, but to scan a foot a cell phone camera and free mobile apps are sufficient. It is important for the object to be totally still during the scan, so it is recommended to ask an assistant to scan your feet. For a good scan you will need bright even lighting, a good quality camera, and an object of known size (like an A4 page) for scale reference. Scan one foot at a time, in a standing position, with no socks.
3D modeling
A shoe last is a unique 3D modeling challenge. It must have accurate dimensions to fit the foot, as well as graceful curves to look elegant. In addition the last must suit the shoe style and manufacturing process. Achieving all this with 3D modelling software requires skill and experience, combined with input and collaboration from the client. The advantage of 3D printing is that custom or prototype lasts can be produced at a fraction of the cost and time compared to traditional lasts.
3D print
3D printing using a polymer called PETG has proved to be ideal for the manufacture of shoe lasts. This material is tough enough to take hammer impacts, high temperatures and even nails without breaking. To split the last, a tapered dovetail joint has been developed. This complex geometry is only feasable with 3D printing, and works perfectly for removing the last from the shoe.
