Print this, put it on a robot, and you will be added to the project.

Each wheel (two halves) takes 11g of filament and about 2 hours to print.  There are two different models exported to flip the direction of the 45 degree offset, like regular Mecanum wheels.  The holes in the center of the rim are also rotated, so that you have a reference for which one you have in your hand when you go to assemble them.

The filaments press fit nicely right now and the model didn't require any cleanup at all.  Print with 'combing' enabled, but 'avoid printed areas' turned off.  The overhang resulting from the increasing diameter from base to top is just about perfect, but you'll probably need to go a little slower and have good cooling to keep it looking clean.

The OpenSCAD was a little hasty, and is not really parametric.  It will need some tweaking to scale and modify things.

As modeled, this has a 5mm shaft size, is 30mm wide, and 90mm in diameter right now.  It takes 30 sections of 80mm length of 2.8mm OD string trimmer filament.

But that could be whatever is needed.  Going very much larger will require thicker filament (and I don't think they make it thicker), going smaller will require thinner.  The upper limit for the size could also be fixed by making the rim larger, which would allow for using more filaments.  At the extreme, you could also set them up alternating, weave them, and get a Mars rover style tire.  Just let me know.

It could also use a way to keep the two halves from spinning with regard to each other, like indexing pin holes.  Right now if you compress the entire tire, the center halves rotate against each other.  Conversely, if you spin the two halves with regard to each other, you can change the tire size!  Useful?  Probably not, but who knows what people will think up...