[blanc_p]

OK, no, we misunderstood each other.
The threading should be on the robot controller side.
You need to have the robot moving and the extruder extruding in parallel.

Did you read this section of the documentation?
//m.sinclairbody.com/doc/en/Robot-Machining.html#Print3D
Jeremy

Yes I have read it. I use this code to print.
I explore the possibility to drive a stepper motor by sending steps from the digital outputs. That's why I'm asking you. With your system it's works well...

So the threading is done in the post processor?
Or I have to add a sub program in program events?
How wan we setup extruder like external axis ?