Motor gear ratio explained
There are two pulleys and a timing belt connecting the motor and the paddles.
Depending on your model, the ratio between the two pulleys differs. On nearly all roasters up to p16, we had a 1:1 gear ratio, meaning the two pulleys were of equal size.
Check your gear ratio settings in the service menu if you are experiencing issues with the motor, either by a warning message on the touchscreen, odd movements, or sounds from the drum. What gear ratio your machine should have depends on the model (what pulley ratio it has) and if the PCB has the r25 chip or not:
1:1 gearing + r25 on PCB = 1:1 gear ratio in service menu
2:1 gearing + r25 on PCB = 2:1 gear ratio in service menu
3:1 gearing + r25 on PCB = 3:1 gear ratio in service menu
1:1 gearing – (minus) r25 on PCB = 4:1 gear ratio in service menu
2:1 gearing - (minus) r25 on PCB = 8:1 gear ratio in service menu
3:1 gearing - (minus) r25 on PCB = 12:1 gear ratio in service menu