Extruder starts fine and then is spinning too fast (grinding filament)

Hello,

this is my first entry. My best greetings to all!
I finished my Mendel90 two weeks ago. My first prints were fine and I started to tweak the things (new Slic3r, more calibration etc.)
But now - my extruder is acting strange.

I use the oozefree gcode from nophead. This is printed normal as before, but as soon as the skirt starts the extruder starts to spin too fast but is changing between fast and slow. The layer looks inconsistent of course.

- My bed is level
- Extruder is calibrated
- Z Home Pos is set
- all parts and Firmware are unchanged (beside the two settings)

I am trying now for more than 10 evening to fix this... I really appreciate your help. Thank you!



Here are pictures and videos:
[www.dropbox.com]
[www.dropbox.com]
[www.dropbox.com]
[www.dropbox.com]


Here is the beginning of one example gcode:
G28 ; home all axes
G82 ; use absolute distances for extrusion
G1 X0.0 Y98.0 F9000 ; positioning for ooze free preparation
G1Z0.05 ; positioning Extruder close to bed
M104 S185 ; set temperature
M190 S70 ; wait for bed temperature to be reached
M109 S185 ; wait for temperature to be reached
G92 E0 ; set Extruder to 0
G1 X50.0 E5 F200 ; smear 50mm
G1 E-1 F1200 ; retract 1mm
G1Z0.3 ; positioning Extruder on 0.3mm
M113 S1.0 ; set Extruder PWM (Power)
M108 S17.14 ; set Extruder Speed
G1 X7.031 Y-29.132 Z0.3 F12000.0 ; move to position, set feedrate to 12'000mm/min (=200mm/s)
G1 F1200.0 ; set feedrate to 1200mm/min (=20mm/s)
G1 E1.0 ; extrude 1mm
G1 F12000.0 ; set feedrate to 12000mm/min (=200mm/s)
M101 ; Turn extruder on, undo retraction (make the extruder ready for extrusion)
G1 X12.733 Y-16.651 F1440.0 E1.21855
G1 X36.065 Y-16.056 E1.62681
G1 X38.830 Y-15.354 E1.67671
G1 X39.625 Y-14.948 E1.69233
G1 X41.664 Y-13.314 E1.73803
G1 X42.286 Y-12.562 E1.75509
G1 X42.810 Y-11.828 E1.77087
G1 X43.360 Y-10.933 E1.78925
G1 X44.188 Y-8.828 E1.82882
G1 X44.218 Y-6.453 E1.87035
G1 X43.687 Y-3.401 E1.92456
G1 X43.099 Y-1.618 E1.95739
G1 X39.882 Y4.801 E2.08298
G1 X39.009 Y6.112 E2.11053
G1 X36.611 Y8.906 E2.17493
G1 X35.934 Y9.584 E2.19169
G1 X34.173 Y11.105 E2.23240
G1 X32.792 Y12.018 E2.26136
G1 X28.823 Y13.959 E2.33864
G1 X27.531 Y14.428 E2.36269
G1 X21.835 Y15.830 E2.46528
G1 X18.213 Y16.547 E2.52988
G1 X14.270 Y17.258 E2.59995
G1 X10.362 Y17.872 E2.66915

Looks like you are using volumetric extrusion and firmware retraction. I don't think either are support in the firmware shipped with the kit.

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[www.hydraraptor.blogspot.com]

Thank you for your fast answer.
So, what do I have to change in my slicer software?

in my Slic3r are this settings all unchecked:
"Use relative E distances"
"Use firmware retraction"
"Use volumetric E"

Edited 1 time(s). Last edit at 06/18/2015 08:30AM by Tengushi.

Seems solved, I remembered in your documentation, that relative E distances has to be activated. I tried this setting several times and nothing changed.

But now it seems to work. *strange*
I've started now a print and it works. Will check with another print afterwards.

Seems the problem exists between chair and keyboard... )

Thank you for your time!!!!

The firmware defaults to relative E but it can be switched to absolute E with M82. For some reason your gcode started with G82 to do that but that isn't a valid code as far as I can see.

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[www.hydraraptor.blogspot.com]