Made them for my Cats. I glued them with hot glue under shoe boxes and the cats can now roll around. I used a 2mm TIG welding rod as axle but will try making a version that uses the 1.75mm filament as axle. A drill may be required to smooth out the inner holes of the wheel and the holder.

The wheel is small but can handle some load very fine. Can be used on other applications aswell.