First of all You have to check the correct spindle control in each GearStep:
- check the mechanical gear ratio:
program M3 S60 and SPCOF and count the really effective revolutions at spindle side in each GearStep. You need to adjust 31050/60 with the mechanical assembled gearStep-Ratio to get 1 mechanical revolution in 1 sec - independend from display on HMI
- check the encoder response:
pending on the numbers of encoders and the interface signals to activate the encoder make sure one spindle revolution causes 360deg in display (axis diagnosis screen)
usually the first encoder is located directly on the motor shaft and the second encoder is connected 1:1 to the spindle shaft.
For a correct spindle response the 2nd encoder need to be declared as "direct encoder" MD ENC_IS_DIRECT=1. and the ratio in 31080/90 need to be declared as the mechanical ratio of coupling - mostly 1:1.
You have to check the interface signal for encoder activation as well. Do You select the first or the second encoder for position control?
I'm not really sure - but the 802 provides only 1 interface signal for encoder activation. Am I right? If You want to activate the second encoder, You need to swap the encoder activation in MD 30230.
To get a better overview please answer these questions:
- how many encoder do You use at the spindle?
- Where are the spindle related encoders assembled on? what ratio?
- where did You define the encoder data now - encoder dataset  or ?
result of Your first cutting:
- does the pitch of thread match to the programmed value?
hope that helps
hope that helps