My Mill or Their Code?

G28 is used for homing on 3D printers, not sure what GRBL uses it for.

I found about a year ago that I was supposed to use grbl/grbl processor for linuxcnc. I also found that again recently as i had forgotten. What processor should i be using? 3 axis cnc mill.

Thanks,
John

Bumbino wrote:

I found about a year ago that I was supposed to use grbl/grbl processor for linuxcnc. I also found that again recently as i had forgotten. What processor should i be using? 3 axis cnc mill.

Thanks,
John
 

Well, I guess you can use whatever suits your machine BUT I don't see any reason why the Autodesk HSM post for Linuxcnc mill would not work with Linuxcnc mill. Then I've also checked that the latest version of grbl post also allow you to choose G53 or G28.  

My suggestion would be to first try selecting G53 with your current grbl post processor and see if that correct the problem the way you want your machine to work. If not then it is just a matter of downloading the LinuxCnc post, install it and select it when you process it. You can this way easily switch posts to compare the file generated by both.

The other thing is that you must also have the minimum required 'post engine version'.for a given post. This is not a problem if you have the latest Fusion 360 (2023) but if not fusion may fail when processing the files. Have a look here: forums.autodesk.com/t5/hsm-post-processo...update/td-p/10182498   Not linuxCnc but related same way.

 

Good writing about G28 vs G53: www.mmsonline.com/articles/g28-versus-g53
 

Bumbino wrote:

I found about a year ago that I was supposed to use grbl/grbl processor for linuxcnc. I also found that again recently as i had forgotten. What processor should i be using? 3 axis cnc mill.

Thanks,
John
 

Found out how?  From where or whom?

And what mill or controller do you have?  Brand (if purchased), controller and controller software would help nail down exactly what the issue is.

Everyone responding has already identified the most likely two culprits: wrong post processor, or wrong interpretation of what "machine Z0" actually means to the controller.

But without some more details on the machine you're going to be going through trial and error with your finger on the E-stop button in full-clench mode.

Ok. So good progress. I have no idea how I didn't see linuxcnc emc processor there. First what i did was take an old file processed with grbl so it has the G28 stuff that was crashing me and load it up. I jogged to a good safe height, issued a G28.1 and reloaded the file. The lines driving through the table and work went away. I see a safe travel path to the work surface!

I made a file using linuxcnc as the processor and it's doing N20 G53 G0 Z0 at the top. I'm trying but i haven't figured out yet how to program G53. The projected travel path for this takes my spindle from a safe place down into the table and drives up into work piece... basically same as the G28 was doing.

Just wanted to give an update. You all are helping and i'm doing my best to make sense of the documentation.

Thanks,
John