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Just getting started on planning my AXYZ cnc router retrofit. Regarding the “AXYZ AXI” stepper drivers, the wiring diagram I have indicates driver control is standard 3 cable (12vdc, step, dir). Dip switches have the micro steps set to 1200 micro steps/rev (default). Is there anything else I need to know?

The stock spindle inverter was replaced with an eTrac X2C and is currently wired with 6 wires (gnd, decelerate, accelerate,  5vdc, feedback, on/off). Is there anything else I should consider?

My current plan is to purchase a Mesa 7i96s. For a pc, I have a Dell Optiplex 7050 and an ELO touchscreen ready to go.

Backstory, the AMC controller board on the small AXYZ cnc router that I bought is bad. It shows ‘Error 92’ or no controller OS and the AXYZ tool path software is unable to communicate with the board to restore it. My plan had been to convert the machine to Linuxcnc anyways but it would have been nice to test it and take some measurements prior to starting the conversion.

If you are using the 7I96S, and its encoder interface is free,
you can setup homing to index, using encoder feedback.

If you do not want to use encoder feedback, you can use
7i96s_esdid1.bin firmware that supports homing  to index on
step/dir channel 0. Note that you don't need a full
encoder for this as only the index signal is used.

It either case, I would assume you have the encoder with index
on the motor and the home switch on the A axis.

I would like to get started on a LinuxCNC based three axis machine and keep the costs low.  Based on reading extensively on the web, I have decided to try with a RPI5 as the host and some flavor Remora.  The Remora part has me totally uncertain.  I going for simple.  I have read the Remora pages and it seems like SPI is a good bet.  The question is what HW for the Remora.  So multiple Bigtreetech "SKR" boards are listed as tested but the ones I see for sale are often listed as "mini" (does that make a difference) ??? and more concerning, list GD prefix main processors, not the STM  processors that are listed as tested in the Remora pages.  Are any of the Bigtreetech SKR boards with GD prefix processors known to work with Remora?  I would really appreciate some help in figuring out which low cost HW to buy that gives me a good chance of it working and not requiring low level hacking.  TIA.

Its probably repairable. If it was an output short, its likely just a damaged
MOSFET ( NDT3055 ) A 7I37TA will work as a replacement, but you need to
change the wiring as Andy mentioned.

Here's the BOM:


 
 

I’m running LinuxCNC 2.9.4 on a fanless Venoen P12B with a PREEMPT_RT kernel and EtherCAT (IgH master + lcec HAL driver) connected to 5x EL8-EC400(COE) drives via an Intel I225-V NIC using thedriver. Everything initializes correctly—slaves reach OP state, clocks sync, link is stable at 100Mb/s Full Duplex—but I still get intermittent motion jitter, especially after reboot.shows good average latency (~2 µs) but occasional spikes up to 95 µs. I’ve tried kernel parameters likebut that worsened the issue, likely due to the system’s passive cooling. I’d like to keep my current hardware and am looking for any software-based solution to eliminate jitter with thedriver. Any help is greatly appreciated!

it seems to be a conventional quadrature encoder, so it should be easy to integrate without any complex VHD changes, but this will depend on what interface hardware you are using.

You might find it better to home to a simple flag on the axis though, especially if you are using stepper motors and have no other feedback.

Also bear in mind that in many cases the orientation of the workpiece in the axis is not repeatable (for example for work held in a lathe chuck), and so homing isn't any help. My own A axis is set up to just home without moving, and then I touch-off the work orientation with a dial indicator or spirit level.

To not answer your question....
If the backlog of counts is causing a problem, you can enable:

joint.N.jog-vel-mode IN BIT

When FALSE (the default), the jogwheel operates in position mode. The joint will move exactly jog-scale units for each count, regardless of how long that might take. When TRUE, the wheel operates in velocity mode - motion stops when the wheel stops, even if that means the commanded motion is not completed.


If you can find where in the motion code the "backlog" exists then you could connect it to one of the supplied "debug" parameters:
github.com/LinuxCNC/linuxcnc/blob/master...motion/motion.c#L556

These are already set up in the code, you just need to assign values to (for example) emcmot_hal_data->debug_float_0 to see that number in the HAL.
(and recompile LinuxCNC)

I think you can probably use a 7i37-TA, but it will need to be wired differently.
But a repair might well be possible.

You mean, that you didn`t tune your Servos at all?
In my world a Servo need to be tuned connected to the machine and the load it has to work with to work properly and performant.