open loop servo tuning.

I'm using Universal stepper controller made by pico systems.
i'm using a 3 servo system, 2 angular and 1 linear ,all are running in open loop.

2 angular are yashkawa make.
axis 2 (in my ini file) 400 w (1.3Nm rated torque/rated speed 3000rpm) reducer of 5:1 //
servo pulse / rotation =72000//
axis 1 (in my ini file) 840 w (5.39 Nm rated torque/rated speed 1500rpm) reducer of 10:1 //
servo pulse / rotation =36000//

1 linear servo
axis 0 (in my ini file) 750 w (rated torque 2.4Nm//rated speed 3000rpm) ball screw pitch 25 mm /
rotation //servo pusle/roation = 100000//

i cant get it to move to speed of motors capabilites
max it moves is at 70 mm /min
above that it throws line 2 following error.
please guide me in pointing out my error.


i'm attaching my ini file with this thread.

and also the name plate of all three servos.

in the ini
line 112
MAX_VELOCITY = 3.20 = 192mm/min '''''''''''''''''''''''''''
go for
MAX_VELOCITY = 100.0
DEFAULT_ACCELERATION = 30.0
MAX_ACCELERATION = 500.0
STEPGEN_MAXACCEL = 750.0

ALSO into the AXIS or Joints

STEPGEN_MAXACCEL = 750.0


4000 steps per mm is quite high on open loop servos

Thanks for the reply,.
reducing 4000 steps /mm to lower values like 400steps / mm gives me a joint 2 following error.

you cand simply reduce the SCALE it is a Hardware combination to the elektronics count

so if your hardware realy got 4000steps per mm the scale must be the value

is it ok with the 4000steps and does the mashine move the value you commanded
lets say with a dial
Forward backwards 0,1mm

i am not sure, but i think it doesnt move to the correct destination,
and i really want to have a lower pulses / mm (My line driver IC doesnt support these high frequencies).
but i get joint 2 following error in linux CNC if i reduce pulses / mm.
it would be great if you guide me a work around to reducing pulses/mm

What are your following error limits?

And what are the stepgen limits set to?

How do i find them?
is it hardware related?

Those are Linuxcnc configuration settings found in your ini file.

My ini files doesnt have those values.

skvallab wrote: My ini files doesnt have those values.

Where did your INI file originate from?