RPi5 Scale settings

Hi I has problem with my setup  ini file  I do not understand the behavior of this if I use 200 step for the scale in my z axle and then G0Z-100 and the movment stop at 40 mm 
step 300 = 60 mm
step 400 =  81mm
step 500 = 78 mm
step 600 = 59 mm
Why can´'t I hit 100 mm in my set up I tryed many diferent value of steps with 50 increasment  
computer = Raspberry Pi 5 ,breakoutboard db25 cinese make , stepperdriver DM542  , 1/4 800 steps , motors 200 steps
are there any kind to help me in the right direction
yours sinserly Krister



   

Are you sure it is not stalling because your accel/velocity values are too high?

if the distance moved with a 100 mm command is not inversely proportional
to the scale, the hardware is not following the  command.

500 mm/s is way faster than is possible.

Even at 300 steps per mm, 500 mm/s  needs a 150 KHz step rate, but your base thread
period limits you to only about 5KHz (5 KHz = about 16.6 mm/sec at 300 steps/mm)

I try tomorow a lower speed . Thank you very much for a quick replay