Duet maestro and weirdness on start gcode

[Veti]

you never answered Phaedrux post about switching to absolute positioning for those moves.

[Agniusm]

@veti I dont know why would it be different as my duet wifi works ok with the same script.
P.S. OK. I have figured it out.
I have placed my move to the fron of the bed before these:
M104 S[first_layer_temperature] ; set extruder temp
M109 S[first_layer_temperature] ; wait for extruder temp
and now it works

[Agniusm]

Case closed;

[Agniusm]

Re-opened. Looks like it does it random. I don't know what is happening. Whenever i sliced with the new start script it went and did how it suppose to. Now prints finished and i started same file again and it again remained at the back of the bed and purged mid air.

[Veti]

as Phaedrux has said multible times in this thread, you need to make sure that when the code is executed it needs to be in absolute positioning . so add the correct G90 and G91 commands to your code.

[Agniusm]

@veti do i need to add it just for that move or the whole start script?

[Veti]

try with a G90 at the beginning

[deckingman]

@agniusm By way of explanation, a relative move such as G1 X10, Y10 will move the print head by 10mm positive in both the X and Y directions. Whereas in absolute mode, that same G1 X10 Y10 will move the print head to the position which is 10mm in both X and Y from the homed position (usually 0,0).

So for example if the print head started at X50 , Y60 then relative G1 X10 Y10 will move the print head another 10mm in each direction and it will end up at X60 Y70. But in absolute mode starting with the print head in that same position of X50 Y60 that same G1 X10 Y10 command will move the print to X10 Y10 so it will move minus 40mm in X and minus 50mm in Y.

In actual fact, all moves have to be relative to some point in space. So absolute moves mean go to an XY position relative to the homed position. Therefore it follows that if the homed position hasn't been established, then any absolute moves aren't going to work properly.

In summary, use relative to move by an amount, use absolute to move to a position (relative to the homed position).

[Phaedrux]

@phaedrux said in Duet maestro and weirdness on start gcode:

@agniusm said in Duet maestro and weirdness on start gcode:

G1 Y0.0 F5000 ; go outside print area
G92 E0 ; reset extrusion distance
G1 X70.0 E9 F1000 ; intro line
G1 X140 E12.5 F1000 ; intro line

I say again, it looks like you're missing G90 and G91 commands here. G1 Y0 makes no sense in the context of a relative move. But the next movements are to extrude a prime like, which would require a relative move.

So the snippet above would become

G90 ; absolute positioning
G1 Y0 X0 F5000 ; go outside print area
G92 E0 ; reset extrusion distance
G91 ; relative positioning
G1 X70.0 E9  F1000 ; intro line
G1 X140 E12.5  F1000 ; intro line

[Agniusm]

@deckingman Thanks. Yes, i am familiar with what those command do and how they work.
Adding G90 at the begining of the move and G91 after seems to have solved the problem, at least on couple prints i did so far.
Thanks