Hello all, I am new to cnc milling. I am having a problem and can't figure out a solution. As stated above when i start a new job with the bit in the start position and X, Y, and Z set to Zero, the machine drives the bity straight down and crashes my machine. I have looked into the g-code and don't see anything that would cause the problem. I am hoping for some help figuring this out, I have put all the information I have below. Post Processor - Fusion 360 with grbl selected Open Builds Blackbox motion control system The g-code file is attached Any help would be appreciated. Paul
Did you remember to Home prior to setting Zero? You also need to Home, to establish Machine Coordinates. SetZero just sets Work Coordinates.
The machine needs to be 'selfaware' as to size and orientation and this means it needs to home to establish this knowledge. If the machine has home switches then enable homing and use it. If it does not have home switches then you will have to fake it.
The stock GRBL post supplied with Fusion is not very good, we recommend using our OB post docs:software:fusion360 [OpenBuilds Documentation]
Edit the Gcode at the beginning. Change the G54 line to G0 Z5.5 then go to the end of the G code and delete all the G code lines after Z5.5. Keep the M lines. This will stop the plunge at the beginning. When the file is run, it will go to Z5.5 and stop.
Not solid advice, there may be more G53s not just at the beginning. And deleting lines without understanding them (as most beginners would not) is not ideal either. Rather, do the right thing: HOME - other coordinate systems also depend on a solid home reference - really no excuse not to and a lot easier on everyone involved. The POST is well designed, all you need to do, is HOME Read up a little more about Coordinate systems, and how Machine coordinates are the base, and every other (G54-59.1 and also G28, G30, etc) are but offsets from the Machine Coordinates and you will realize the importance of Homing
The Home All button is still even easier - but thanks for trying to help Checkout unresolved threads and feel free to help out in future
