retract causes filament to slip out

Here is what I mean.
After a long retract, the filament is pulled out so much that it slips out of the hotend, but is still gripped by the extruder. The extruder then chews up the filament because it gets stuck in the space between the extruder and hotend. Slic3r is set to only retract 1mm (default) but it think it retracts more than that.
Any suggestions?

Hi,

Does your filament look like this [forums.reprap.org] when you pull it out of the extruder?
I think we have the same problem here...

Here is my post: [forums.reprap.org]

Mine looks like this:

Looks almost like mine - there is a kink...

I think i solved this problem (again) !

At my first print a few weeks ago I had the same problem - this was because I had not enough space between the noozle and the heated bed. I fixed this and everything works fine.

Until now - But this time it was much simpler to fix! I fixed all problems and were printing all the time - and this was the failure!
I was too lazy to wait for the extruder to heat up - so I left it on, let the print cool down, changed a few models, printed again, and so on. In this time the extruder was ready to go at 190-200°.

Don't do that ;-) !!! Turn the extruder of after the print is finished - also retire 3 mm so no filament will be heated up until the extruder cools.

The order to print is important, too!

What I'm doing now:
- heat the bed and wait for it
- heat the extruder
- click "start job" BEFORE the extruder is on it's temperature

-> the printer goes in start position, heats the extruder and immediately starts printing. So the filament has no time to melt before the print job begins.

Sounds crazy but I'm printing the whole day now - and everything is fine :-)

DAMN! And again :-( I thought I have found the failure........but it happens again! And now immediately at layer 2 or 3 :-(

Edited 1 time(s). Last edit at 06/08/2013 04:13PM by Killi.

I've been starting to get this problem too, but it only happens when I set my layer height to 0.2mm or less, at 0.3mm all seems to work fine.

Still no idea how to fix so staying a 0.3mm for the moment,

That's not the problem - I'm on 0.3mm since I got that printer...

I think Ohmarinus got it! Please look here: http://forums.reprap.org/read.php?262,216370