Making timing pulley - putting theory into action

[Jonathan]

Very good job anyway. I like the side rings which I couldn't be bothered :whistling:
Doesn't fly cutter do job faster???

The flanges are nice. You should use 2 to 4 per pair of pulleys, depending on the orientation.

Ball nose cutter puts less load on the spindle, so less wear? More likely reason is probably that it's harder to grind an accurate 3mm form tool (unless you've got the right equipment) than to just use a ball nose cutter.