I was surprised by the lack of cupholder designs so put this one together for my scooter, which is a typical adult-sized scooter on Amazon. It's perfectly sized to hold a typical 12 or 16oz can, and its overall shape is modeled after cans as well. The cupholder attaches with six M3 bolts and nuts. A thin sheet of TPU works well to increase the grip between the cupholder clamps and the scooter. The first profile includes a version with a can-shaped bottom, which requires some supports around the bottom rim, and the second is a cylinder version that doesn't need supports. There are also some disassembled versions of the parts in case you need to customize the clamps to fit your specific scooter or adjust the size.

It turns out, there are a couple challenges when transporting a can attached to a scooter… #1 being that your drink sloshes around and splashes everywhere, and #2 being that the can rattles constantly.

Problem #1 is solved with a TPU lid that snaps into place. I modified a version of this soda saver design from dekopuma, adding a second tab with a hole for a tether, a protrusion shaped to the top of the can to reduce the amount that can splash up and pool on top of the can, and a centered hold for pressure relief (carbonated drinks will make the lid explode off otherwise!). You can see in the photos that it fits tightly enough to hold a full 16oz can. I included a version of the lid without the hole as well.

Problem #2 requires some kind of dampening at the bottom of the cup holder. I tried several 95A TPU designs and settled on a puck design that works well. The profile on the object uses very sparse rectilinear infill so it has a good amount of squish. There's some small protruding tabs that help hold it in place as well. This definitely resolves the rattling issue quite well, but a softer material will do a better job of minimizing splashing.

I suggest printing the TPU parts using the provided profiles, it took a good amount of trial and error to get them right.