Unfortunately I don't have access to a lathe so might just have to search around for some decent caster/RC wheels or something of the like. Although I will soon have a 3D printer... no idea whether abs or pla plastic will be tough enough for hubs though.

By the sounds of it they seem like very popular tx/rx's in the robot world, so I shall definitely add them to my shopping list.

I don't suppose you know anywhere that cuts HDPE and steel/hardox to order do you? Only I see some roboteers getting ready-cut flatpack armour sent via post, would be a good idea for me seen as I have no experience handling such materials