@dsherburn
Most CNC machines use home switches to establish an origin on the machine and soft limits to establish the work envelope for the machine. The work offsets (G54 through G59) give you a way to save the coordinates for a reference location inside your work envelope and call it up in your program using the G54 through G59 work offset reference. That way you can program your part using a known location on the part without worrying about where it is on the machine. This gives you more options when you want to use different size stock or various size machines.
The DRO buttons give you a way to save a temporary offset location called G92. The syntax for G92 temporary offsets are explained
here. If you see the G92 number at the bottom of the screen then you are in temporary offset mode. To get out this mode you simply open the MDI panel and enter G92.1 to return to G54 mode. If you want to use the other work offsets you can activate them the same way using the MDI panel and typing in the G55 through G59 numbers.
I find DRO buttons useful when setting up my machine to align it with a specific feature on a part. In an example setup that already has hole in it I would:
- Jog a probe into a hole with G54 active
- Slowly move along an axis until I contact the edge of the hole on that axis.
- Then press the DRO button to zero on that point to activate the G92 temporary work offset.
- Then move in the opposite direction until it contacts the other edge and note the distance measured on the DRO.
- Then I would use the G01 command to move half that value away from that edge and repeat in the other axis to accurately find the center of the hole.
After that you can then press the DRO button again or simply use the G54 table to save the new location. To save that new location I open the work offsets table and set the G54 offset value for that axis using the autoload feature. Once the G54 values are set I include a G54 command at the start of the G-Code program so that it goes to that location.
Its important to note that Masso defaults to G54 on startup so whatever value is set for G54 in the table will be the location that it starts cutting from when you start the program. If you don't enter G54 in your program Masso will still start that either the G54 location or the G92 location if its active.
I was confused by this at first also. With a little practice this will become second nature. Hope this helps.
Cheers, Stephen Brown