Min Ferror & Ferror

Hello to everyone, I'm configuring the lathe with mesa 5i22-1 in step / dir mode and I noticed that running the G76 failed me tracking axes.
I solved by raising the values to min.ferror 1 and ferror 5.
Now thread 1000 rounds 10 without blocking.
I was wondering: being open-loop on the emc side, does the ferror value make sense?
I do not think so, so I could even raise him 5min and 25th, what do you say?

I forgot that they are in G21 mm mode

my lathe

A thank you to BillyKid and Andypugh

if you get a (large) following error on a open loop step/dir system it means the step generator
is not following the commanded position well.

This can be because of insufficient acceleration or velocity headroom
(stepgen limits should be about 25% greater than machine limits)
or tuning if the stepgen is PID controlled

Can you post your hal/ini files?

Here are the files in the machine.
Thank you

try replacing all the (per axis)

setp pid.N.maxerror .0005

statements with

setp pid.N.maxerror 0

(where N is the axis)

And in the ini file, delete the min ferror and ferror rows?

But if imposed 0 does not become more critical?

Is it not better to put false in place of true?

You should be able to set the ferror and min ferror much smaller (say .01 mm and .005 mm)

I do not understand the position control utility when controlling it drives.

Where do I not understand?

PCW wrote:

try replacing all the (per axis)

setp pid.N.maxerror .0005

statements with

setp pid.N.maxerror 0

(where N is the axis)

Hello,

sorry but i try to understand what this change means. Is this only for testing, or should this parameter set to 0 all the time? Does this mean that no more errors allowed or that no more errors are stored for this pin? Most configuration examples that i saw use a value of .0005.

Sorry for my question but i have a really hard time to wrap my head around the Stepper - PID - FERROR and tuning configuration.

No, those are permanent changes.

The pid.N.maxerror setting is not directly related to following error at all but rather
bounds the PID error (difference between commanded and feedback position)
A setting of 0 mean no bounding is applied. This is documented in the pid manual:

man pid

(at the command line)

You can also set the maxerror to say .01 which will work, but .0005 is too small a number for
metric setups. (this is a pncconf bug, it should use different numbers for inch vs mm machines)

The point of setting the pid.N.maxerror is to prevent large bogus velocity corrections if the
host device has large latency spikes, this is not very likely so disabling the bounding is not
harmful on most machines.

The problem with pncconfs default setting of .0005 on metric configurations is that this is only
a 0.5 micron error which allows only a .5 mm/second correction velocity so you can run out of
correction headroom (for timebase differences for example) on a fast machine

Thanks for the explanation.

I use a MESA 7i76e, Lichuan Closed-Loop Steppers (LC57H380 + LCDA357H) and ballscrews on X and Y with a pitch of 10 and was not able to get higher speed than 8 m/min.

After changing the pid.N.maxerror value to 0 i am able to go up to 14 m/min and propably even higher.

Are there any advantages if i set the value to 0.1 or is it ok to let it disabled by the value of 0?