Weird Z axis problem

K8200 3D Printer K8200 - Issues while printing
1

Well… since I can’t figure out this problem on my own, I’ve come to seek help on the forums.

The situation:
My printer works perfectly, if I use a certain spot on my printbed.
For example, this works great: (yeh I know… bad placement)
puu.sh/fUYKx/873fc9a369.png

However, if I try to make something near the edge of the start:
puu.sh/fUYMT/6102dd73e0.png

The printer will home, lift the Z - heat and extrude a bit when hot (start procedure).
Starting the print, it’ll try to go to the first point of the printing object, … but somehow at this moment the Z axis (going down, to z= 0.0… or something) will like block/stop working/… you can hear it’s trying to move down but it can’t.

The problem occurs on CuraEngine (slow AND fast settings) BUT NOT ON SLIC3R!
Does anyone has any idea what could cause this?
I personally have better results with CuraEngine (faster & better results)

more info:
this works (puu.sh/fV0Dn/0c9fe4339e.png)
this doesn’t (puu.sh/fV0JP/72da3f884c.png)
not 100% sure it’s due to moving it to the right of moving it a little bit up… :confused:
will test this and shall aswell post a video of the blocking movement tomorrow.

2

Check your start g-code in cura for unwanted z movements.
Perhaps post it here for “analysis”.

cheers,

Christian

3

image: http://puu.sh/fZCw2/41fa9ca544.jpg
G code:

[code];Generated with Cura_SteamEngine 14.12
; Default start code
G28 ; Home extruder

G1 Z15 F150

M107 ; Turn off fan

G90 ; Absolute positioning

M82 ; Extruder in absolute mode

M190 S35 ; Activate all used extruder

M104 T0 S187
G92 E0 ; Reset extruder position
; Wait for all used extruders to reach temperature

M109 T0 S187

G92 E0 ;zero the extruded length
G1 F200 E10 ;extrude 10mm of feed stock
G92 E0 ;zero the extruded length again
;Layer count: 2
;LAYER:0
M107
G0 F9000 X3.980 Y31.437 Z0.500
;TYPE:SKIRT
G1 F1800 X66.480 Y31.437 E2.32101
G1 X66.480 Y32.003 E2.34203
G1 X117.545 Y32.003 E4.23839
G1 X117.612 Y31.153 E4.27005
G1 X117.951 Y29.741 E4.32398
G1 X118.508 Y28.395 E4.37807
G1 X119.270 Y27.154 E4.43215
G1 X120.213 Y26.050 E4.48607
G1 X121.317 Y25.107 E4.53999
G1 X122.558 Y24.345 E4.59407
G1 X123.904 Y23.788 E4.64817
G1 X125.316 Y23.449 E4.70209
G1 X126.521 Y23.354 E4.74698
G1 X160.017 Y23.354 E5.99089
G1 X160.017 Y24.197 E6.02220
…
[/code]

It either blocks at
G0 F9000 X3.980 Y31.437 Z0.500
or
G1 F1800 X66.480 Y31.437 E2.32101

as I’m not sure about what this exactly means, I actually tried just to edit the startup g-code.
Changed to:

[code];Generated with Cura_SteamEngine 14.12
; Default start code
G28 ; Home extruder
G1 Z15 F150
M107 ; Turn off fan

G90 ; Absolute positioning
M82 ; Extruder in absolute mode
M190 S35 ; Activate all used extruder

M104 T0 S187
G92 E0 ; Reset extruder position
; Wait for all used extruders to reach temperature

M109 T0 S187

G92 E0 ;zero the extruded length
G1 F200 E10 ;extrude 10mm of feed stock
G92 E0 ;zero the extruded length again

G91; Change to relative positioning
G1 F1800; Slow movement of X, Y axis
G1 X20 Y20; Move X, Y 20mm
G1 F250; Slow movement of Z axis
G28 Z; Home Z
G90
[/code]
So move to X20 Y20
then Home Z

(edit: planning to change it to move to X150 instead of X20 Y20 - that way the extra extruded feed won’t be a problem)

This actually solved the problem, but I’d love to know what actually causes the blocks (knowing what I can and can’t do with my printer)

4

Did repetier show an endstop hit message when the “blocking” occured?
Try firmware v2 if you not already use it. It disables the endstops during print.