My first extrusion

[Ted Roller]

My first extrusion of PLA.  Originally I set the temp to 174C but the auger motor seemed to be very sluggish.  I reset the temp to 180C and the motor seemed to run much easier.  I checked the filament diameter with cheap-o digital calipers consistantly at 1.5 mm.  The thinner diameter could be due to the fact that I let the filament hang off the counter rather than spool it up (I don't have a spool yet).  Here's a video... https://www.youtube.com/watch?v=doUUYPI7IJw

[Raymond Luo]

Ted, your experiences with PLA is different from mine.

The stock PLA pellets that came with the Extrusionbot kit extrudes consistently with good tolerances (+-.08mm) between 158 to 160 degree celsius and at good speed.

Other observations:

I found that between 174-165 the PLA will turn to liquid and flow freely out of the nozzle (even without the main motor driving it). 

At 155 the motor would really have to work for very little extrusion.

Further the freshly extruded filament is extremely sensitive pulling pressures and minute tugs can have significant impact on dimensional accuracy. Hanging off from gravity seems to be subtle enough to not have an impact though, seems to be my hands. I'm not sure how gentle the spooler would be on the filament though.

Seeing that you posted a picture of PLA pellets from OSPrinting LLC, I think you were using a different batch of PLA which would account for the difference.