Making timing pulley - putting theory into action

[wiatroda]

Impressive that your router is rigid enough for that. I did mine on the milling machine using the same process and it clearly put a lot of force on the spindle.
I believe the term is form tool. Not that it's really matters...
I agree entirely. I found it difficult to get a perfect mesh with the belt. The theoretical values for the pulley blank diameter never seemed quite right.

I think it is rigid. Whole construction is milled from 6mm thick steel plate + 100x50 rectangular profile. After I paint it I'll make some pics.

hmm,maybe fly-cutter does not apply entirely. Anyway It's ground from broken end mill to create tooth profile or rather between-tooth-profile . My cutter rests safely and wait for next job .
Calculations worked for me:
pulleys PCD radius - 0.381mm gives you pulley radius.
then cut depth if 1.21mm.
However I found slight dimensional variations for pulley dia /doc. I used those from pic uploaded