Weird retraction sound

I’ve been getting this sound with my printer lately.
I’ve narrowed it down to the retraction motion. If I change my retraction speed in slicer from 30 mm/s to 20 mm/s I do not hear this sound and get much nicer prints – although they take a lot longer & are bit more blobby. I find a retraction speed of25 works well, but I still hear the sound from time to time.

I’ve experimented with various retraction lengths (when retraction speed is still at 30) and get the same sound.

I’ve experimented will various tension screw distances and also cleaned the hobbolt.

http://www.youtube.com/watch?v=2h9hrUHDYOg - see time points: 0:00,0:05, 0:012-0:15,0:27

bed: 85
hot end: 230
slicer - fast profile on lulzbot website
newest pronterface
ABS (I’ve tried 2 different colors with the same result)

This is typical for any model i print. Obviously more so with models that require more retration.

Thanks!
Aaron

I had the same problem. The extruder motor is being driven too hard and it is losing steps.

Check this thread. This fixed the problem for me. A-retract is the setting to adjust to get rid of the noise and step loss. In my case it would retract fine then lose steps on the return from retraction. If I had a part with a lot of retraction, it would actually pull the filament right out of the hot end causing the print to fail.

https://forum.lulzbot.com/t/retraction-problem-ideas/349/1

Nvm chaning it to 900 was the best thing i could have ever done to my printer. Shes running great now and parts are no longer coming out and being able tobe pulled apart