Hi DaveX,
thanks for your answer. Yes I use repetier, but it is really bad commented and sometimes hard to decifrate, at least for me.
Anyhow I reached a similar conclusion too but then I didn't understand why they use just one virtual axis.
I able to follow your lead in this example of yours, it is an easy one, where the three axis have to move of the same number of steps.
For instance if the cartesian coordinate is g1 x20 y25 z15, and ( following what you wrote at the end) the delta axis is a segment parallel to the vector
that describe the move, I'm not able to understand why is necessary to create such a segment...
or maybe I just misunderstood your explanation.
Once again thanks and I hope you have the will to help me again.