Made these for a Mii Sword Fighter cosplay. This listing includes the waist buckle that says Mii on it, in two sizes, and a buckle for the Sword Fighter's chest.
The waist buckle can be printed as one solid part or two for easier printing. For the two-piece belt, simply glue the two pieces together.
The small waist buckle measures approximately 85 mm x 74 mm x 15 mm. The large waist buckle measures approximately 110 mm x 96 mm x 15 mm. The chest buckle measures approximately 82 mm x 70 mm x 12 mm.
These models can be resized pretty reliably though they are designed for a 2 inch (50 mm) thick and 1.5 inch (38 mm) thick belt.