The mecanum wheels have 12 rollers each. Each roller needs an axle. Some designs use small metal rods. This project uses plastic.
The 3D printer filament is almost a perfect solution. The only problem is that is comes on a spool and this is curved.
Here is how to make straight pins using filament.
- the axle pin has a flat head
- start with a length of filament
- place it on a smooth flat surface and warm it with a hot air gun
- when it starts to soften, roll it back and forth with between two flat surfaces
- it will cool as a straight length of filament
- use a candle to soften the end
- press the softened end against a smooth metal surface
- this forms the head of the axle pin
- the finished axle pin holds a roller in the mecanum wheel hub