Z axis freezes

[VBill 0]

hello
I use an anet A8 with the original firmware and CURA since version 3.5.

Since version 3.6 I have some problems:
On some parts the Z axis freezes.
For example my last print which is a total of 17mm high with supports, the printing starts and works very well up to 7.9mm then the Z axis remains locked at this value, but the printing of the layers does not stop. This damages the print head.

I tried to regenerate the gcode: idem
Other printing can be done without any problem
 

Of course I checked the functioning of the Z axis in manual mode and there is no problem.

Does anyone have any idea

Edited March 2 by VBill

[VBill 0]

you can see conception here : https://www.tinkercad.com/things/jGtl7Fm6RlE-bouchon-reservoire

[VBill 0]

My Cura profile : https://drive.google.com/file/d/1y8SF37k-5CYBk128MLVfaw_8yi1os8UR/view?usp=sharing

 

My gcode start :

G21 ;valeurs métriques

G90 ;positionnement absolu

M82 ;mettre l'extrudeuse en mode absolu

M107 ;commencez avec le ventilateur éteint

G28 X0 Y0 ;déplacer X / Y à des butées min

G28 Z0 ;déplacez Z en butées min

G0 X0 Y15 F9000 ;Lit en avant

G0 Z0.15 ;Déposer au lit

G92 E0 ;zéro la longueur extrudée

G1 X40 E10 F500 ;Extruder 10 mm de filament sur 4 cm

G92 E0 ;zéro la longueur extrudée

G1 E-1 F500 ;Rétracter un peu

G1 X80 F4000 ;Essuye rapidement la ligne de filament

G1 Z0.3 ;Levez et commencez à imprimer.

G1 F9000 ;Message imprimer

M117 Impression...

 

End :

M104 S0 ;chauffage de l'extrudeuse éteint

M140 S0 ;chauffe-lit chauffant éteint

G91 ;positionnement relatif

G1 E-1 F300 ;rétracter un peu le filament avant de soulever la buse, pour libérer une partie de la pression

G1 Z+0.5 E-5 X-20 Y-20 F9000 ;déplacez Z un peu et retirez le filament encore plus

G28 X0 Y0 ;déplacez X / Y jusqu'à la butée min, de sorte que la tête soit à l'écart

G90 ;positionnement absolu

G1 Y190 F9000 ;le lit se déplace vers l'avant

M84 ;steppers off

[gr5 1,155]

Search your gcode file for the letter "Z".  It appears several times at the top of the file but then only once per layer.  Look at those values and see if something goes wrong at some point.

 

I strongly suspect cura is fine and something is wrong with the Z axis.  Maybe the feedrate is too fast for your printer.  It will be the F number on the same line as the Z.  The F value is in mm/minute so it's 60 times larger than the speed in mm/sec.  Example:

 

G0 Z12.1 F6000

 

That would move to position nozzle 12.1mm above glass and at a speed of 100mm/sec (6000/60=100).

 

 

 

[VBill 0]

Hello
I have performed several checks including the gcode (thanks gr5)
I didn't find anything strange and the printing was blocked on the Z axis at the end of the support (6.9mm for my part)
Finally I started again from the basic PLA Fine setting on CURA and is modified some parameters (temp, wall etc) and now everything works.

This is all weird.
Greetings