GCode file doesn't do what I expect

Hi All, I need some help before I go mad and broke ... Also I hope that this is in the right discussion thread - happy to move it elsewhere if so advised

I have managed to set up LinuxCNC and configure it to run my CNC mill. Using the keyboard to jog all the axis' works fine and without any issues. The problem I am having is when it comes to run a file.

Here are the steps I am taking:

1. Jog the tool to the front left corner of the mill, just touching the spoil board
2. Set all axis as home at this point - however I have noticed that the values for X, Y and Z are not changed to '0' when I do this
3. Jog the machine to the required starting point on the material and 'Touch Off' X and Y axis
4. Check that the machine has enough range of movement for the job
5. Move the Z axis to the top of the material and 'Touch Off' this axis
6. Run the job

At this point I am expecting the Z axis to lift about 5mm move to the starting point on the job and get stuck in. Instead I am usually getting an error message that says that one or more of the axis exceed the machine limits, and when I choose, Continue Anyway, it just plunges the tool straight down through the material.

So far I am on my 4th end mill bit, and have decided that enough is enough and the challenge is outside of my skill set to resolve.

Not sure what files I should attach to help out so if anyone thinks that they might know what is causing the issues, let me know what you need to help confirm and I will provide

Thanks again in advance

Thanks tommylight, hopefully these are what you need. I have also attached the test file I was trying out.

The router is a 6040 I purchased off 'EvilBay' some time ago but have recently moved from MACH3 and having to set it all up again

Work ares dimensions are:
X = 280mm
Y = 390mm
Z= 55mm

Touch off points were at X60; Y70, Z20
Cheers

Thanks tommylight for this, will adjust the config file in the morning so Z axis is from -55 to 0 rather than 0 to 55, and then give it another go

I am learning to use Fusion360 as my CAD / CAM software, because my previous choices (Solidworks and Vectric Aspire) are now no longer within my budget. I wioll also adjust my test file CAM output to reflect your suggestions

Cheers and thanks again

Thank you andypugh to pick up that while I was incorrect I was not that wrong.

There is so much to learn as you move from one environment, piece of software, to another.

I am only just figuring out some of the basics and asking questions on forums is a learning process as well for me.

The information on the internet can be great but also very confusing at times for the newcomer as a level a prior knowledge is often expected from those that make the information available.

Cheers

I have modified the post processor to not do the initial G53 zero move (only because the machine is large and slow). Doing that in your case would allow you to put your Z machine coordinates as either +55 or -55 at the top.
Saying that, on all the mills i have ever used,G53 Z0 is always at the top of travel, going to negative. I guess whoever writes fusion post processors are assuming this.

Now i think about it though, the machine bed at Z0 does sound logical...