Stringing on Pillar Help

[BeEazy 0]

Hello, I am new to 3D printing and am currently optimizing my Ultimaker 2 Extended+ using Cura. (2.85mm PLA)

 

I am in the process of changing retraction settings, but am having trouble. I am currently printing pillars, but keep running into the same issue. As the pillars get taller, they get thinner at the top, and my printer ends up printing the tops too fast, causing stringing. I'm not exactly sure which setting I can change to make the tops print slower. Any advice?
 

[gr5 1,252]

This is called a torture test for good reason.  The filament doesn't get much time.  You want to set the travel speed as fast as possible but it's going to string a little no matter what.  These strings are pretty easy to remove by hand.  One thing you can try is lowering the temperature.  A lot.  Maybe even as low as 180C  but be careful as the filament gets more viscous and you might get underextrusion if you print too fast at 180C.  You could also print with a smaller nozzle such as the .25.  Make sure fan is at 100% but that's the default so you can't do much there.

 

[BeEazy 0]

On 6/25/2018 at 7:05 PM, gr5 said:

This is called a torture test for good reason.  The filament doesn't get much time.  You want to set the travel speed as fast as possible but it's going to string a little no matter what.  These strings are pretty easy to remove by hand.  One thing you can try is lowering the temperature.  A lot.  Maybe even as low as 180C  but be careful as the filament gets more viscous and you might get underextrusion if you print too fast at 180C.  You could also print with a smaller nozzle such as the .25.  Make sure fan is at 100% but that's the default so you can't do much there.

 

 

I tried lowering the temperature to 185C, and still had stringing, but it was less than previously. I am looking at "Retraction Extra Prime Amount" on Cura, and notice that by default it is set to 0 mm^3. Should I leave this unchanged, or do you have a recommended volume?

[gr5 1,252]

I don't know if you can get those tiny spikes any better.   Well if you go to a 0.25mm nozzle or smaller and keep lowering the temp - maybe even to 160C (but you have to change the cold extrusion limit if you go that low).  That's what I would try.  

 

But I recommend you move on to some other test or try an actual print because "tiny spikes on top of a print" is not a typical feature.  There are many other things hard to print.  I think it's best to concentrate on what you actually need to print first, then move onto test parts to concentrate on a particular feature you care about.