After setting the parameters of the board I am to cut through, defining cut depth, Z height (I am not using a probe) and calibrating the zero point but the cutting process stops before reaching the defined value.
Have checked for mechanical reasons, and made sure that defined values are correct, still cannot figure out why I’m not getting what I see on the work surface. I’m defining tabs so the program realizes that I want to cut thru but doesn’t!
Well I have read you reply Haldor and I think if you read the following it amounts to the same thing.
I lower the bit to my zero point so the it is just touching the upper surface of the board I wish to cut. This board is approx 3mm thick. This is my reference point. I then choose the cutting depth as 3mm + approx 1mm = total 4mm. Is this not the same as you suggest? This procedure does not result in a cut right through the board, so it certainly has something to do with a reference point.
If your step/mm value is off AND/OR mechanical aspect isnt perfect then measuring on top of the material to be cut wont result in a good carve.
When setting your Z-zero manually jog the bit down to the spoil board, then command a 4mm retract jog. (jogging incrementally untill the bit is raised 4mm void this excersise) If the bit dont raise above the material thats the first clue the step/mm value may be off.
If the spoil board is used as Z-reference, and commanded to raise 4mm and Z-zero is at this height, then a 4mm deep carve will end at exactly spoil board level. (Cut through)
The GRBL parameter for Z is $102, if measured motion is half of whats commanded you need to change $102-value to twice of current. To change simply write $102=new value and press Enter.
Power controller OFF/ON and check using $$ that the new value is in place.
So if your current $102=100 the new value should be 200.
($120 is the acceleration value for the X-axis and not relevant for this issue )