So I just finished my MPCNC build a few days ago and it’s all working well using manual controls and everything. I’m using Aspire to do my toolpaths and have followed all the tutorials to set up just a simple test file. Material thickness is set and it’s set to use origin on top of material and that’s where I Home Z to with my touch plate.
After it homes it raises the Z like 3-4 inches above the top of the material and starts going. I have the z probe offset set to the thickness of my touch plate but it’s only 0.5mm so definitely not enough to compensate. I’m supposing I could just set the offset to a large value to compensate but I’d really rather figure out the root cause of the problem.
Do you mean the gcode file that was output by the post processor? I have one that is set to use mm and one set to use inches. The dxf file was drawn in inches so I ran it through the inch gcode PP.
Well I just tried that and it still is printing about 2.5-3 inches above the material surface. I even tried experimenting with changing the Z Offset to -40.0mm and it didn’t move the tool closer to the surface at all.
I am going to pull a fresh copy of Marlin 2.0 and reset everything and see if that does anything.
You let.is start to print correct not just move to first cut it will pull up and then move to first position. Dubble check material setup on my machine I wouldn’t have that much room to move in z 3 inch up total
G91 ; Coordenadas en modo Relativo.
G0 Z1.270 ; Subir Z para ir a Origen y que no rasque la broca el material
G90 ; Coordenadas en Posiciones absolutas.
G20 ; Unidades en mm.
M84 ; Apagar Motores Paso a paso.
G28 X ; Ir a Origen X
G28 Y ; Ir a Origen Y
G92 Z1.270 ; Le indica a la Maquina donde se encuentra de manera relativa el (eje
Z)
; Estando por tanto el Punto CERO del Z a Z=-1.270
...
; *************************************
; ** INICIO DE CORTE **
; *************************************
M117 EN PROCESO... ; MENSAJE
;----->
G0 X22.624 Y22.743 Z1.270 F2540.0
G1 Z0.000 F508.0
G1 Y24.013 Z-1.270
G1 Y22.743 Z-2.540
G1 Y33.261 F1270.0
G1 X22.053
G1 X21.235 Y33.323
G1 Y21.235
G1 X22.841
G1 X22.678 Y21.981
G1 X22.624 Y22.743
G1 X23.881
G1 Y34.518
G1 X22.053
G1 X21.513 Y34.554
G1 X20.977 Y34.661
G1 X20.461 Y34.839
G1 X19.977 Y35.082
G1 Y19.977
G1 X24.954
G1 X24.583 Y20.449
G1 X24.281 Y20.978
G1 X24.059 Y21.550
G1 X23.925 Y22.145
G1 X23.881 Y22.743
G0 Z1.270 F2540.0
G0 X27.984 Y21.156
G1 Z0.000 F508.0
G1 X27.775 Y21.170 Z-0.209
G1 X27.567 Y21.212 Z-0.421
G1 X27.364 Y21.282 Z-0.636
G1 X27.173 Y21.379 Z-0.850
G1 X26.998 Y21.499 Z-1.063
G1 X26.843 Y21.639 Z-1.270
G1 X26.998 Y21.499 Z-1.479
G1 X27.173 Y21.379 Z-1.691
G1 X27.364 Y21.282 Z-1.906
G1 X27.567 Y21.212 Z-2.120
G1 X27.775 Y21.170 Z-2.333
G1 X27.984 Y21.156 Z-2.540
G1 X27.753 Y21.173 F1270.0
G1 X27.517 Y21.226
G1 X27.283 Y21.319
G1 X27.061 Y21.451
G1 X26.861 Y21.621
G1 X26.692 Y21.821
The PP was written in Spanish and I haven’t taken the time to translate it all to English for final output yet but pretty self explanatory. I have a decent understanding of GCode and I can’t see anything wrong with it so hopefully you can pick up something I missed.
It does, yes. All axis move in the correct directions when homing and manual moves. Base on the gcode that is getting put out by the software I imagine that it is moving in the correct direction based on those commands but it is hard to tell since they happen quickly and are 1-2mm distances, but I have no reason to believe they aren’t other than the fact that the machine raises too high on Z to start with. But if it were reading them backward I would assume it would drive by Z axis into my table.
The G20 gcode is telling the machine to treat all units as inches. Is that intentional? I think that the feedarates (F2540 etc) are WAY too high when interpreted as inches per min.
I had modified it at one point to treat everything as inches since I designed the file in inches in Aspire and wasn’t sure if it should output as inches or mm. I’ve since learned it needs to match the machine, regardless of how the it was dimensioned in Aspire and actually did change it back to G21 in the GCode that is on the SD card for the machine but forgot to switch it in the one I posted.
I did just notice however that it is only set to do G28 for X and Y and then sets the Z manually, however when I begin the print it homes all three axis, so not sure what’s going on with that.
The current process it does when I start the print file on the machine is: Home X, Home Y, Home Z, Raise Z far away from the material surface, Lower Z slightly, Begin tool path.
From the GCode it doesn’t ever call for a Home Z G28 yet it homes Z anyway. So could it be homing and then raising up then doing G92 Z1.270?
