I have a project that requires some ‘exact’ positioning. I am running Avid’s plug and play with their Mach4 screen… I have another CNC for small engraving that allow the input of a ‘go to’ location. How do you do that from the Avid Mach4 screen. As in 'go to X4.255 Y500 without changing start xy location for the project. I am also trying to get the most from the Mach4 wizard that allows changes to CV setting for cutting accurate small non concentric holes… at the recommendation of Avid I have changed the gears on all 4 motors… anyone else struggling with this?
You could use the MDI to input gcode manually.
Look into G0 and G1 codes (they’re simple to understand) and the MDI tab in Mach4.
It would look something like (presuming metric):
G0 X4.255 Y500. (This would be a rapid move, full speed)
G1 X4.255 Y500. F1500 (This would be a controlled move limited to 1500mm/s)
Note that I think it’s recommended to include that decimal for axis values - I don’t remember why, I think I saw a note in the Mach4 user’s guide.
If you mean “move to an absolute X/Y coordinate on the table, relative to the machine origin”, then you want the G53 command. It tells the corresponding G0/G1 to use absolute coordinates instead of the active work offset (i.e. ignores G54)
G53 G0 X1 Y1 Z-1
Moves to 1 inch away from the end stops, for example
Warning: this doesn’t change the work offset, so the next non-G53 move will jump back to your G54 origin. You have to put G53 on all the moves that you want absolute.
In my code, I typically follow the G53 with a G91 (relative distance mode) to make coding easier, then G90 when I’m done.
Or you can use G92 to set a temporary origin, and G92.1 to cancel it.
not to be picky, but I run a Shopbot tool also, and they have a box where you put in the X and / or Y coordinate you want to move the machine and hit enter… to all of us that learned only ‘pictures, scales, etc’ gcode can be scary… is there someone at Avid that looks at the forum for suggestions on screen design ?
You could edit the Mach 4 screen set to add this feature. Jim Neeb (JN woodworks) is good at screen editing. He has a couple of great videos on YouTube.
Thats what I would do if you want something convenient that you use a lot.
I have buttons and shortcuts for going to front, middle, back and return to last in my screen. However, it would be relatively easy to add the ability to input specific values as well. Here is a video on screen editing Mach4 Screen Editing & new screen features for CNC laser support including laser touch plate support - YouTube, and my screens are here Mach4 Screen Stuff - Google Drive that have plenty of code exaples of moving to absolute positions, and how take input from DRO’s on the screen.
If you don’t do this too often, then using the MDI window as stated above is great because once you get used to that you can do lots of things really quickly when needed.
And yet you have no problem using much more complex tools like CAD and CAM to move it around and cut stuff.
I agree, most of what is in a Gcode file is actually very simple, and with just a bit of reading you can pick it up very quickly. Much simpler than learning a CAD program. Anyone running a CNC should really pick up the basics at least because that is ultimately what your machine is being told to do so when things go south, it kinda splits the problem in half to the machine or the content generation side.
All good points, designing screens, learning gcode… fear is loosing control of the assest while i figure out what I screwed up.t That being said, if you want things your way…figure out how to customize. I appreciate the input. Thanks all
Take a 1/4" collet and put a long 1/4" dowel in it and then set up an obstacle course and never issue a Z command and you won’t break anything. I promise!
Set the Z height and leave it and just command around the table using the dowel on the X and Y. At worse it will complain about being commanded over the soft limits.
It is a skill that will greatly improve your machining abilities.