Slic3r freaks out completely after a few layers

I have printed a few prints with Slic3r successfully, but my latest prints have been plagued by a weird problem. One object was downloaded from thingiverse and one I made myself. The print started out great, I was printing slightly slow, at 30-40 mm/s.

The first 4-5 layers went great, and then the printer just completely freaked out, printing at what looked like 150 mm/s or something, making rough stops and turns, slamming and etc, and completely ruining the print.

Does anyone know what might cause this?

... check your G-code for changes in speed ...

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Viktor
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Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]

Huh... So I looked at the gcode... This is what I found:

G1 Z1.850 F3000.000 ; move to next layer (4)
G1 X67.866 Y103.363 ; move to first perimeter point
G1 F9000.000 E30.00000 ; compensate retraction
G1 X32.134 Y103.363 F1500.000 E74.42719 ; perimeter
G1 X32.134 Y46.637 E144.95897 ; perimeter
G1 X67.866 Y46.637 E189.38616 ; perimeter
G1 X67.866 Y103.303 E259.84335 ; perimeter
G1 X68.286 Y103.783 F3000.000 ; move to first perimeter point
G1 X31.714 Y103.783 F1500.000 E305.31495 ; perimeter
G1 X31.714 Y46.217 E376.89116 ; perimeter
G1 X68.286 Y46.217 E422.36276 ; perimeter
G1 X68.286 Y103.723 E493.86437 ; perimeter
G1 F9000.000 E463.86437 ; retract
G92 E0 ; reset extrusion distance
G1 X32.682 Y103.040 F3000.000 ; move to first fill point
G1 F9000.000 E30.00000 ; compensate retraction
G1 X32.426 Y102.847 F0.000 E30.38377 ; fill

I figured "F" specifies the speed. Here it says zero. I can imagine that would cause some problems, and it is it the rough position of the code I would guess it happened. Why does it say 0 I wonder?

Oh. I see now 0 is exactly what I have specified for top layer speed. Doh. -.-

Anyway, since obviously some fools accidentally write stupid stuff like this, maybe a warning could pop up in slic3r, since no one would obviously be interested in printing at 0 speed...

... another hint - remove all the comments, as they can cause some weird behaviour too ... either uncheck the option in the creating program, or run a script, that splits the line after a ';' and outputs in a new file ...

Edited 1 time(s). Last edit at 09/25/2012 08:55AM by VDX.

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Viktor
--------
Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]