Extruder constantly extrudes

[wayne 0]

Hi,

I'm using PLA and I have tried setting the temp to 210 and 200 but PLA constantly emerges from the extruder nozzle.

Has anyone seen this before?

Regards

Wayne

 

[illuminarti 18]

Assuming that the extruder gear isn't turning constantly, then this is just the natural ooze that happens due to thermal expansion and/or gravity.

You need to be sure to prime the extruder when starting a print by pre-extruding a few mm as part of your starting gcode and/or printing several loops of skirt, to make sure that the melt chamber gets filled back up with plastic before you start printing your actual object.

But apart from that, it's harmless, and can be ignored.

 

[aaron 2]

If you are not using a brim, be sure to pre-extrude until you have a consistent stream of molten plastic coming out the nozzle. First layer is very important.

 

[gr5 2,210]

Assuming there is nothing wrong with your ultimaker (and there might be..), then you should also be aware that the faster you print, the higher the pressures get in the print nozzle so that when you want to stop printing, it keeps coming out.

The way to fix this isn't necessarily to print colder because then the pressures get higher. On the other hand colder means "more like toothpaste" so colder can help.

A better way is to print slower. Having said that, 210C at 40mm/sec with .2mm layers is reasonably slow enough that you tend not to get too much leakage but if you are unhappy with the quality then try 25mm/sec or 15mm/sec and just be patient and wait for that print.

Also there is a feature that should be on by default i believe called "retraction". This tries to immediately remove all the pressure in the nozzle and is used when the head is jumping over a spot that should have no extrusion but is outside the print. When retraction isn't working quite right we call it "stringing".