Hello, I have a Monoprice Select Mini V2 and I’ve recently been having issues with little strings that are thick and sturdy sticking off of models:

I used Cura v3.4.1 to slice this model: https://www.thingiverse.com/thing:2563909 using Hatchbox Black PLA filament

And the following settings:

Layer Height: 0.1313 mm
Wall Thickness 1.05 mm
Infill: 22%
Extruder Temp: 200 C
Bed Temp: 55 C
Retraction Distance: 4 mm
Retraction Speed: 40 mm/s
Speed: 50 mm/s
Z-Hop When Retracted: Off
Supports: Off
Adhesion: Brim

I’d appreciate any advice on how to fix this problem, thank you.

This looks like the head is moving away from the print while hot material is still oozing out. Depending on the software you can enable coast to end, and do not leave print perimeter. The issue with the later is that this looks like it happens every time the head moves to the other shaft. Coast to end will let you set a distance from the end of each line that the extruder will stop pushing in order to drop off pressure from expanding hot plastic. This should help a little.

By the way it may simply be my own in experience but I typically disable the retraction options and I very often do not use Z hop.

At some point I would like to find out how to use that code correctly myself and get good results. But in most cases I find the coast to end command to be most suitable.

I find the Z hop to occasionally be useful depending on the complexity of the part that I am doing. The reason why I find the retraction and Coast Z hop functions to be suspect is because, very often as the head lifts away it leaves a very small stem or flange of material behind it. This has a nasty effect of causing problems later when the head comes back over to smooth out the area that now has a stem left in there causing a greater defect overtime.

Your 3D printer is showing a stringy appearance due to over-extrusion and this occurs due to multiplier or flow setting in your slicing software.

To resolve this, open the slicer software and check the extrusion multiplier selection. Besides, you can also decrease the flow settings in the 3D printer software to get assistance.

I actually have my retractions speed set to 80mm/sec and retracting 8mm! It seems to work pretty well for me, along with having my temps down around 190°C. I’m using a different filament though.