How do I choose the right shape of pulleys for driving belts?

One of the pulleys must be crowned to ensure that the Belt stays properly on the pulleys.
Preferably one of the large Pulleys and/or with a large contact arc.

Calculation of the radius of the pulley crowns:

Calcul du rayon des bombés de poulies
Pulley diameter Height of crown h
mm mm
up to 112 0.3
from 112 to 140 0.4
from 140 to 180 0.5
from 180 to 224 0.6
from 224 to 355 0.8
from 355 to 500 1
from 500 to 1000 1.2

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