The pulleys and shafts are fairly straight forward although there is some close tolerance required on the shafts.
The shafts are made from drill rod, it machines very well and is already the correct diameter. The heads have flats to fit in slots on the support. The ends are drill 2.5mm and then tapped for m3 socket head cap screws.
The nuts are also made from drill rod. I drilled and tapped, then milled them square but leaving a small part of the round as decoration.
The pulleys are made from stainless steel. I have a lot of this in the correct diameter. After the first few cuts I remembered that the SFM (surface speed) is considerably slower than for steel. This improved the finish a lot. The sides of the pulleys are only 1mm wide, not very forgiving appearance wise. The hole for shaft was drilled and then reamed to exactly 5mm. A close but smooth fit on the shafts.