<p>Is the firts time that I saw this movement after the printing has finishig and causes the nozzle crashes to the printed part and I noticed due the part is 14x8 and the nozzle is to near and below to the border of the shape. I supposed that some scripts has changed but, seems to be everything ok.</p>

<p>this is the end script:</p>

<pre><code>G92 E0
G1 E-1.5000 F1800
; layer end
M104 S0 ; turn off extruder
M140 S0 ; turn off bed
G28 X0  ; home X axis
M84 ; disable motors
; Build Summary
;   Build time: 3 hours 9 minutes
;   Filament length: 12689.1 mm (12.69 m)
;   Plastic volume: 30520.78 mm^3 (30.52 cc)
;   Plastic weight: 38.15 g (0.08 lb)
</code></pre>

<p>Z axis moves down 4mm after finishing going to X0, why? I don't want the nozzle crashes the part on going to zero.</p>

You can use:
```
```
G91
G1 Z10
```
```
```
G91
```
make the printer use ralative positioning, while
```
G1 Z10
```
would move the gantry up of 10mm, reagrdless of its actual position.
In order to understand what's going on, you could experiment with the position of those lines in the script.
The safest bet it to insert them at the very top, but you could insert them straight after the homing of the X axis to understand if the drop you are seeing is caused by the homing command itself or by the ´M84´ one.
My
guess
is that the drop is actually caused by the latter.
```
M84
```
doesn't really "disable motors", rather it stops using energy to keep them still (i.e.: it stops the
idle hold
).  What I believe is happening in your case is that when you stop the idle hold, the weight and mechanical play of the X gantry causes it to move slightly (a bit like when you relax your body on the sofa and you "sink" in it a bit more).