Radical start up

I have an issue when cutting or carving a new project.
When downloading a tool pass ( Vcarvepro) to gesender and testing the boundary, everything works fine, however, when I start the job, the router drives to a completely different start position different position and plunges down below the set Z deeps. After a few attempts, the router finally starts at the correct start point and finished the job correctly. I’m not sure if gsender mixes up the code when jogging too much to set the start point on the work? Any constructive help would be aprriceiated.

Is there some G28-Command within the first lines of the Gcode?

when setting start point and zero X,Y,Z, I did not see any G28 code

@wooddy Welcome to the group Dieter.

What CNC machine are you using?

Do you have homing/limit switches installed?

I have a Bluey CNC Machine (made in Australia). The fitted limit switches are not connected.
I have had the machine for only a few weeks and done some good work with it, I also use a laser unit with the machine, where I use the Lightburn software, which gives me no trouble.
Maybe there are some settings wrong in gsender I just don’t know enough about these settings. I do work in mm. ???

@wooddy Reading a bit on the Bluey site, it looks like it runs on a proprietary controller using an arduino and grbl 1.1. What post processor are you using in VCarve. I suggest that you should be using grbl mm.

Thank you for your input. I use a X-Carve (mm) (*.gcode). post-processor
But I believe it could be the settings in the gsender program, which I don’t quite figured out yet.

@wooddy Just a question: why did you choose xcarve mm for your post? Is this recommended by Bluey?

It can be x carve* . gcode . or gcode both will work, the issue I have is that the machine worked on these settings and I did some great 3D carving with it until I came to the issue I previously mentioned.

@wooddy Not knowing anything about your CNC, I can’t help you much.

A logical first step would be to determine what you changed between the time that all was well and the project that the problem started.

Also, is the problem confined to this one project or does the problem now exist for projects that ran fine previously?