Extruder position print resume

makb

Hello all,

I have the following problem, I use a syringe instead of an extruder and after emptying it, I change it and insert a new syringe. I pause my print job and start it again after inserting the new one. The problem is that the last extruder position is always approached and the syringe is always completely emptied. How can I change this approach to the last position?

Thank you very much.

Many greetings
MAKB

Repetier

Interesting. I know several users using syringe without having that problem. What we do is we remember the position at pause start and before continue we reset the position with G92 Epos so print continues where it stopped.

Question would be more why does that empty your syringe. G92 does normally not move extruder. Actually if new pos is now E0 due to homing it would define real E0 to be handles as position Estored_pos so it does not cause this problem.

What might be the case is that your change procedure changes silently the extrusion mode to relative while you was absolute before the change. In that case switch to absolue E positions after change. Marlin does change positioning mode on homing, but not sure what it does with syringe.

makb

Can you tell me what the command in the firmware might be so that I can change or comment something out.

Repetier

Which command do you use for changing the syringe? I know that G28 does this, so if G28 E0 resets syringe position that might be the command.

Repetier

Also if you do it on printer display we will not see such things like mode change. Here it would help to add in continue script a command to set correct E mode

- M82 - Set E codes absolute (default)

- M83 - Set E codes relative while in Absolute Coordinates (G90) mode
But that requires that you slice all your g-code with same mode.