Stringy Prints

[printerfan 5]

I just installed the official heated bed upgrade on my UMO and now I am experiencing stringy prints. Any advice on how to fix? Do I need to adjust my bed?

 

[printerfan 5]

I ran a bed leveling pattern and adjusted as it printed. Afterwards I printed a different print, which resulted in a better, but still not ideal print. The print is nearly flowless on the front, back, and left side. However, on the right side, both items that I printed have tons of strings even though the design does not have much if any overhang...

Not sure what to do to fix this?

 

[pm_dude 27]

Did you print both pieces one next to the other? It could be simply that the print head is jumping from one object to the other and create those strings.

What print settings do you use? Strings often happen when the temp is too high.

 

[printerfan 5]

When I went back into cura it turns out one of the objects is inverted relative to how I thought it was on the plate. So the stringing was between the items. I was printing "all at once", print speed 30 mm/s, .1 mm layer height, 150 movement speed, 210C nozzle temp, 70C bed temp, the above grey prints used Ultimaker brand filament.

Wondering what to adjust to reduce the stringing between objects?

Also, just put in a spool of Protoparadigm PLA and prints are looking even more stringy and "chewed up", despite printing one object even at a slow 20mm/s print speed.

 

[DidierKlein 729]

At such a slow speed you can drop the printing temperature. It depends on the filament but you can probably go down to 190°c - 200°c.

To reduce stringing you can also increase the travel speed, to 200m/s or more (i know the UM2 handles 250mm/s with no problems)

 

[printerfan 5]

I can see how increasing the travel speed would potentially reduce the strings between multiple objects when printing "all at once", but how do I get rid of the "chewed up" look of the single object prints that are in the picture using the Blue Protoparadigm filament in the picture above?

 

[bigmouse 6]

Have you tried playing with retraction amount! Like increasing it! Ctrl + E

 

[IRobertI 516]

The chewed up look is due to excessive heat is my guess. First, reduce your bed temperature. 70C is way too high for PLA, try 50C instead (for very small prints you might even get away with no heat at all).

Make sure your fans are going full blast and try reducing your print temperature as already mentioned. At such a low speed and layer height you're not pushing much plastic at all and you should be able to get away with 200C I would think.

You're already using "all at once" so I wont suggest that. But if your objects are very close together on the platform it might be hard for the fans to reach. In that case you could try moving the pieces apart a bit.

 

[printerfan 5]

Unfortunately, I do not have a hotend fan yet. I bought my UMO used and for whatever reason the previous owner removed it. I will try 50C bed temp and 200C nozzle temp and see if that makes a difference. Also, do you recommend 2.85 mm or 3.0 mm diameter settting in Cura for Protoparadigm PLA filament?

 

[IRobertI 516]

No fan explains it. You'll get much better results once you put a fan on there.

I recommend that you measure the filament carefully and use that measurement in cura. Measure it at several spots over a meter long section of the filament and use the average value of that in cura. If it's actually 3mm thick the printer may have trouble feeding it properly, just an FYI.

 

[printerfan 5]

Well, I didn't have these issues with the Ultimaker brand filament and I didn't have a fan then either. I slowed the print down to 20 mm/s print speed, 200C nozzle, 50C bed, and have tried both 2.85 and 3.0 mm diameter, same results.

Maybe it is the lack of fan, but I just don't understand why I was able to get decent quality on prints with the Ultimaker Filament but not the Protoparadigm filament?

 

[pm_dude 27]

What setting value is the minimum layer time? Enable cold head lift in the expert settings.

[printerfan 5]

Minimum layer time is 5.

 

[printerfan 5]

I keep making changes in Cura settings based on everyone's suggestions, but unfortunately my prints are still bad.

 

 

[pm_dude 27]

You need to install that fan asap

[printerfan 5]

Okay, I'm going to order a fan.

What fan is ideal? I found this one below:

http://www.ebay.com/itm/171560866172?_trksid=p2060778.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT

Also, not sure where to plug the fan into because it looks like the slots on the top of the printer head are already being used for something?

 

 

[printerfan 5]

Forgot to mention the previous owner install dual extrusion on my UMO, so maybe the 2 pin plugs are for the second extruder?

I just don't know where I am supposed to plug a 2 pin fan into given the slots appear occupied on the print head?

 

[printerfan 5]

Finally decided to try a different color filament by the same brand to see if maybe it was just a bad spool of filament.

 

In this newest print, the printhead completely misses both ultibots on both their left and right sides several times causing massive PLA strands to get dumped next to and partially hanging off the ultibot prints.

 

 

[pm_dude 27]

What version of the Ultirobot are you printing? It doesn't seems to have support for the hands.

Refer to the assembly manual to check the fan assembly:

https://www.ultimaker.com/spree/uploads/240/original/Ultimaker_Original_assembly_manual_v1.1.pdf

See sections:

6.3.2. Step 2: cooling fan assembly

6.6.4. Step 4: connecting the print head electronics

There is a Fan pack on the Ultimaker store:

https://shop.ultimaker.com/product/41/FanPack

 

[printerfan 5]

 

[printerfan 5]

I'm not sure which Ultibot version I am using, is there a way I can link the STL file on here?

 

[pm_dude 27]

Share a link (google drive/dropbox or diffierent way) or upload a screen shot from cura.

[printerfan 5]

After others viewed the video they concluded the printing path was fine. What I thought was printing too far to the right and left was actually the head attempting to print the ultibot hands. So far the consensus is the majority of the issues is lack of fan causing excessive heating on the print and possibly some overextension contributing to the issue as well.

[printerfan 5]

Pm_dude

Are you wanting a screenshot of the cura settings? If so basic, advanced, and/or expert settings?

[pm_dude 27]

No need for the settings. I was just wondering which version you were printing (with or without supports for the hands)

you can see both versions here: