Homing problem .... help needed

[Karl-Heinz Welter]

Hi

I'm working on my personal openPnP build, ball screws for X/Y, Marlinfw on BTT octopus with CL Nema 21 Steppers (1x X, 2x Y). Latest openPnP Release From March 2026.

Here's my problem:

When I home G28 X Y and do a G1 to X262... Y117.... in a minicom session to the BTT, I always hit the homing fiducial almost bang-on, well +1mm in x-direction. (see video; was captured with openPnP video top camera, switched off machine and minicom to BTT)

Using openPnP, having the exact same coordinates in my Homing fiducial X and Y, hitting the homing button never is anywhere close to the homing fiducial. interestingly enough, the x-axes starts moving way before the y-axis. I don't really care about the latter, but not hitting the fiducial really drives me nuts. I've gone through the fiducial setup dozens of times, always with the same result. With an open-no installation it seems to run smothly.

Any help is more than welcome...

If need be I'll gladly share the machine.xml, I thought I'd spare the upload for now.

Thx for any help

[tonyl...@gmail.com]

Please post your machine.xml file.

[KH W (khtroubleu)]

problem got solved by examining machine.xml with GitHub CoPilot in Visual Studio Code.

There was a "spurious" M18 after the G28 homing command.

homing to fiducial works perfectly now after some additional tweaks to the vision pipeline.