Poor printing quality with lots of stringing :( How can I fix this??

[dennisy38 0]

Retraction speed: 35mm/s

Retraction length: 4.5mm

Buildplate temp: 70

Layer height: 0.1

Shell thickness: 0.8

Nozzle size: 0.4

Printing speed: 50mm/s

Actually I have tried to slow down the printing speed to try to fix the problem, but it didnt do any improvement :(

Do you guys have any suggestion? Thanks

[Dim3nsioneer 521]

Try activating combing, setting travel speed to 250mm/s and retract speed to 45 mm/s. The latter is set on the machine unless you changed the gcode flavor in legacy Cura to RepRap.

[danilius 117]

What material are you using? What machine? What travel speed are you using? What nozzle temperature?

[dennisy38 0]

Try activating combing, setting travel speed to 250mm/s and retract speed to 45 mm/s. The latter is set on the machine unless you changed the gcode flavor in legacy Cura to RepRap.

How to activate combing? I will have a try today! Thanks!

[dennisy38 0]

What material are you using? What machine? What travel speed are you using? What nozzle temperature?

PLA with Ultimaker 2+

Is the travel speed equal to printing speed?

The nozzle temperature is 210

[gr5 1,450]

Activating combing will help a lot. This will keep the head from passing over the open holes mostly. Also printing at a lower temperature and slower will help. For example 200C and 25mm/sec will increase the quality and reduce stringing.

[Dim3nsioneer 521]

How to activate combing? I will have a try today! Thanks!

 

Well, just tick the box...

It's in the 'expert' settings.

[danilius 117]

Rather than spending hours trying to print this case time and time again, simply print two 20mm cubes around 80mm away from each other, and see what happens. If you get stringing between the two, then first start by dialling down the temperature. For this sort of thing it makes sense to watch the printer while it is printing. It might give you some clues.

"Travel speed" <> "print speed". Travel speeds are the non-printing moves, when the hot end stops extruding and moves to another position to start printing again. You can push the UM2 up to 290mm/sec without serious issues.

Also, increase your retraction to 45mm/sec. Speed here makes a difference.

When printing 0.1mm layer heights, you need a lot less temperature than at 0.2, because you are extruding half the volume of plastic compared to 0.2. From what I see here and elsewhere, many people print at 0.2 and give temp values assuming that fact.

[dennisy38 0]

Rather than spending hours trying to print this case time and time again, simply print two 20mm cubes around 80mm away from each other, and see what happens. If you get stringing between the two, then first start by dialling down the temperature. For this sort of thing it makes sense to watch the printer while it is printing. It might give you some clues.

"Travel speed" <> "print speed". Travel speeds are the non-printing moves, when the hot end stops extruding and moves to another position to start printing again. You can push the UM2 up to 290mm/sec without serious issues.

Also, increase your retraction to 45mm/sec. Speed here makes a difference.

When printing 0.1mm layer heights, you need a lot less temperature than at 0.2, because you are extruding half the volume of plastic compared to 0.2. From what I see here and elsewhere, many people print at 0.2 and give temp values assuming that fact.

 

Thanks for your suggestion! I will try to print cubes first!

[valcrow 144]

Also if your nozzle is dirty, you will experience more stringing.

[ivan-lipunov 15]

The curved case at the bottom says that it is not used any glue or capton tape. It makes sense to spend a couple bucks on it.

[geert_2 432]

What I would try in such a case:

- Thorougly clean the outside of the nozzle prior to starting the print, and then wipe it with silicone oil or ptfe oil, to reduce the build-up of molten filament during printing: this gives less "hairs" and less strings. Make very sure to not spoil any ptfe oil on the glass plate, or you will have no bonding at all.

- Gently wipe the glass plate with *salt water* to improve bonding and prevent warping (it seems you have some corners lifting?). This works for PLA only, as far as I know.

- Print speed: 20 to 25mm/s.

- Nozzle temp: 190°C (start the first layer at 210°C for a good bonding, then gradually lower to 190°C and see if that still works). Do not go lower than 180°C.

- Bed temp: 60°C.

- While printing, watch the output and check that you have no over-extrusion (this causes material build-up around the nozzle, and causes hairs and strings).

Some PLA brands and colors do string more than others. So, if you would have more available, try them.