Arbitrary failure (feeder ?)

Hi all,
I’ve just begin to use my Vertex 3D since yesterday. I’ve successfully printed some pieces like the vertex 3D sample ringchain logo. But sometimes the printer just stop feeding or feeds badly : I hear the feeder making an abnormal retraction noise every 2 seconds and I obtain this kind of mess :

I’m using PLA, 200°C, extraction 4mm.

Edit: after taking a closer look it acts like the PLA is stuck or feeder stepper not working well because it just moves forward & back on the same time (!?)

Hi again,
After a few readings in this forum I’ve succeeded to make a print that looks near from good to me :

(if you have any comments, please you’re welcome)

So first of all I moved the Vertex3D printer into a coolest room (~5-10°C ambient air) then I got back to 190°C, 4mm retract, 110mm/s retraction speed, but most important of all, I’ve reduced the flow to 80% (instead of 90% set as default).

Looks acceptable to me.

-The first run I also had problems with the feeder stepper. I reassembled the motor and the black cage around it, and it never made clicking noises again. Probably the pulley touched somewhere. If you disconnect the Teflon tube from the nozzle, you should feel enough pressure on the filament.

-The picture from Alfred in my post shows remarkable results with the green PLA. Apperently different colors give different results. I read somewhere that black gives “the worst” results.

thankyou caph10 for your comment. I had no idea that different colors could have different results (!?). I’ll try the green one at next order ! :wink: