Looking at holonomics/omniwheels..

[savagecreature]

Has anyone tried printing an omniwheel?  I see a few on thingiverse, but I'd think that having PLA/ABS rollers would have a hard time working (friction).  Hmm, maybe spraying with the rubber coating stuff?

I have.  They work pretty well, within a certain context. I agree with you that rubber rollers would be required for what you're trying to do.

I've been looking into Ninjaflex.  it looks like a good solution for a lot of different problems. I'm supposed to have some samples coming from the people that make it. I'll let you know how it all unfolds.

Some examples:

https://www.youtube.com/watch?v=jvxbmcxjois
https://www.youtube.com/watch?v=gTIFs_ILu1w