This is a design for an incredibly specific use-case, but if you're the one-in-a-million person who has the same moped, milk crate, and need to carry stuff around as me, this one's for you.
I was not going to pay $500 for one of Cake's custom aluminum cargo crates for my moped, so I bought this crate from MilkCratesDirect and designed this brace to attach it to the official Makka Rear Carrier using 1.5 inch 5/16" bolts. The crate can be mounted in either orientation.
I printed it in PETG with extra perimeters for added rigidity. You don't need ten bolts, just showing where they could go. I don't know if it'll work with other milk crates.
The author marked this model as their own original creation.