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Hi Guys.
I'm trying to figure out my motor tuning for steps per inch.  I'm guessing I need to use electronic gear ratio in my servo drive to be able to handle the amount of pulses per inch.  Right now if I set an encoder count of (and i'm just playing right now to speed it up)  2500, and a step count of 500000 and I tell it to move .100 it only moves approx. .002 with different variations I can only get approx .011 per .100 request.
So what would be the best electronic ratio
As near as I can figure at this time my ball screws are 5 turns per inch or .200 per rev. (Hardenge SuperSlant, Maybe someone knows for sure the pitch)
it is belt driven from the survo 2 turns of the motor to one turn of the ball screw
The information I find for the motor and encoder says it has 2500 lines per rev.
So I'm thinking  2500x 5(ballscrew)= 12,500 x 2(gearing)= 25000  and this is nothing for a computer to handle but if i work on this figure the axis doesn't move enough to read on a dial indicator.

I am  obviously missing something big because of the amount of pulses I actualy have to put out to get any readable movement per .1 request.
In case you might think it helps.  My survo's and drives are chinese the drives are lichuan A6 drives  Below copied from manual.  I only wanted one line but it would only let me copy from top of page to that line.

A6 Servo Drive User Manual
2
Chapter 2 Electrical Specifications
2.1 Specification
Input power
CONTROL
POWER Single phase 220 VAC
MAIN POWER
SUPPLY Single Phase/Three Phase 220VAC
Working
environment
Temperature 0～45℃
Humidity No condensation ≤90% RH or less
Elevation Altitude ≤1000M
Installation
environment Non-corrosive gases, flammable gases, oil mist or dust, etc.
Installation
method VERTICAL INSTALLATION
Encoder feedback 2500 p/r (resolution: 10000), incremental encode

In the ini file, joint 1 section
HOME_IGNORE_LIMITS = NO
should be
HOME_IGNORE_LIMITS = YES

Use
latency-histogram --nobase --sbinsize 1000 --show
There are a lot of excursions out of the visible area.

You are welcomed, always.

  uploaded the configs.

When you say drives are you meaning the drive boards.. or the servos themselves?
"DIFF/ INPUT Designates differential input speed command terminals."
Thats what the book is calling those terminals if you are meaning on the driver board or cards themselves.

While I was seeing the exact terminology I figured I'd post why I commented on the frequency thing... this is the books description of how the drives work... 
PWM indicates pulse-width modulation which is the operating mode of each transistor in the
controller. In a PWM controller, a power transistor bridge switches a fixed DC bus supply to
the motor load at a constant frequency with varying on-off ratio for output power control. The
SERVOPAK differs from other controllers of its type in that two types of switching techniques
(standard-H and Uni-Switching) are employed.

Anyway, thats a long explanation to say yes I'll find some time tomorrow to see what happens when I do that. The drives are enabled with a ground, and I'm sure they are enabled since it told me how to bypass the enables in the book, and the motors make noise when I enable them. 

These drives also have a lot of adjustments on them, so I assume they are a little different than just a straightforward drive. It appears as though the drives themselves did the tuning more so than the computer did. 

No idea, also didn't see an option to compile for non lts, sometimes things are easier than they seem
Better to set isolcpus=5 or 2-5 because linuxcnc always takes the last core and the quad core a53 is after the 2xa72

Ideally you would set isolcpus=1 but then you need to set the rt tasks to core 1 manually, via a script or change the source of linuxcnc.

royka wrote:

You can try this image, with desktop and gpu hw acceleration but under 1GB:
drive.google.com/file/d/1PCetphqJUFfS3aL...eD7/view?usp=sharing

It's laughable...did not worked tweaking & reweaking to modified it for opi4 ...
your image simply worked as is ...lesson learned here..
i dont understand , if armbian image for opi4 lts work on opi4 why the hell armbian link to non lts ?!?
You tell me , because everything seem to be good .
Trying some isolcpu 1,2 , no latency miracle ,should be ok , cutting air .
Let'see if i can install 2.9.3 now.

Good job Roya ..

I try to get two tandem motor to work. But the moment one side hits the home/limit switch I get the error Cannot unhome while homing, joint 0. So to me it looks like he tries to unhome joint 1 while he still tries to home joint 0

And another question can I somehow let the motors move away from the limit/home switches once they are in a fail state. Because they are tandem I can't just use ignore limits option

So I installed the  SSC tool app on both my laptop- Windows 11 and PC- Windows 10[Intel Lan). The EEPROM app crashed when I tried to scan, it shows nothing connected on either interface. I have tried this as Admin as well.
DHCP is set and I've tried both lan sockets and different cables. The same lan sockets work fine for Internet and file transfer. 
 Could I have missed a network protocol that needs installing to see the servos?