Following error on 400W Delta B3 EtherCAT servos

Hi,
First of all, here is my config:
github.com/zmrdko/3dworks_ethercat_lcec/tree/main

my question is: What is an appropriate/reasonable following error value?

Motors have no load, as they are only tied together and laying on the bench, I tried to autotuned them using AsdaSoft. Even though I am getting around to 0.8 mm ferror during rapids at 12000mm/min (2500rpm, 5mm pitch on ball screw). The following error seems to be related to speed, as 6000mm/min rapids had around 0.4mm ferror and 600mm/min had 0.04mm.

so basically, I know there always will be some following error, but I would like to know, if my following error is not off by one or two decimal points.

BTW: I went through this article: 

wiki.linuxcnc.org/cgi-bin/wiki.pl?Following_Error

and there is broken link to the one and only image (fe2.png)

Thanks!!

Did you check the error from the drive software already?
I would start from there using the Autotune and the "Rigidity" value. That was pretty much the only factor I tuned.
How does your machine mechanics look like? I heard is a lot harder to tune in light weight machines.
But 0,8mm seems way off! It should be in the lower 1/100mm s.
Did you check the fError is after the E-Gear and not before it? Print the values as encoder steps and apply your E-Gear ratio from the settings

Using (older) Delta ASDA M (step/dir) i had an extremely hard time getting a rigid machine. Bandwidth stuck around 50Hz or so, while a stiffer machine should be 100+ . Basically, my router is/was not stiff enough to tune them well. Autotuning is much better tho in the newer versions. Tuning my Z-axis was a breeze (Delta B3).
My router is ~500kg: 
The main issue that i actually had was to get round holes when doing helical boring (faster = worse = due to low gain settings= due to a not super stiff machine). in the end i got it okish. but that was after a lot of hours (20-40 hours) i.e. i tried every combination of every setting..

I know of a guy who retrofitted and old datron with Delta A3. He just autotuned; got super high gain values and had 0 issues at all.