Openbuilds X32 Blackboard - G1 G-code in the Z-axis would not move

It sounds like you were expecting incremental moves - If you were in absolute mode, that behaviour would be correct.

Incremental mode is set by sending the G-code command G91
Absolute mode is set by sending the G-code command G90

Once set, the mode will stay the same until changed (e.g. by running a program).

(It's always good practice to set the mode for the behaviour you expect before sending other commands - also metric / inch mode G20 / G21)

Could that be it?

 

That should put it in incremental mode (G91). That actual command doesn't do anything else though - You could just send G91 on a line of its own.

You can tell what mode the controller is currently in by examining the status that it returns after executing a command:


If the machine is still on, you could scroll back through the messages to see what was happening.

 

Hey! Glad it worked out, and thanks for the feedback

 

It really depends on what you are trying to do. 99.9% of the time I rely on the post processor to generate the GCode (which includes setting the relevant modes) and don't give it any thought. Most of the time you can achieve the same result with either and it's a matter of convenience. It can be quite confusing to try and visualise a long series of relative moves if reading GCode (but that's why we have GCode visualisers!).

It's quite common to switch between them with a manual program - for example if you wanted to manually program a simple operation at several places on the part, it can be convenient to program the actual operation in relative coordinates (G91) and use absolute coordinates (G90) to move to each location - Adding the operation is then just a matter of cutting/pasting the relevant GCode (including the G91 before and the G90 after). Like I said, though, I mostly just leave it to the CAM post processor.