Stringy Prints

[printerfan 5]

When I open the model in cura, it looks like the model on the left without the hand supports (grey/steel colored bot) pictured in your link. In addition, I did not turn on any support setting in Cura when I printed the model.

Many I have talked to believe the lack of nozzle fan has a lot to do with my poor print quality. I will be ordering a fan tonight, any specific brand recommendations?

 

[pm_dude 27]

Do you have the fan mount? If not just pick one on the ultimaker store.

If your model in cura doesnt have the hands supported then you do not have the good model. Check in the samples installed with cura. You should find the one with the hands connected to the sides.

[printerfan 5]

Ended up ordering a 12v 50mmx50mmx12mm fan. I intend to print a shroud for it, hope this resolves my print quality issue.

[printerfan 5]

My nozzle fan came in, but I cannot even print a shroud for it. I attempted to print with ABS for several hours and eventually got the printer to get a print going for 2 hours until it was no longer laying down filament and the result is the following:

ABS, 240C nozzle, 105C bed. 30mm/s print speed, no hotend fan

I need advice, why is my print quality in PLA and ABS so poor? How can I fix this?

 

[upliftedape 0]

I just posted a solution to this as a thread. I did a design of experiments to minimize stringing and maximize resolution.

Admittedly, it's for the brownronze ultimaker PLA.

 

http://imgur.com/a/5HG06#5

Try the following settings for PLA:

Layer Height: 0.06

Shell 0.8

Fill Density 80%

Print speed 150

print temp: 190

Retrac speed: 55

Distance:8

Travel speed 250bottom layer 50

infill 150

outershell 20

inner shell 20

cooling: 1s (yes I know, but it worked really well, you might be surprised.)

Enable cooling: minimum 30

 

[printerfan 5]

PLA, .08 layer hieght,30 mm/s print speed, 210C nozzle, 50C bed, 200% extrusion

 

 

PLA, Cura High Quality Default Settings

 

[printerfan 5]

PLA, .3 Layer height, 30 mm/s print speed, 220C nozzle, 50C bed, 100% extrusion

 

 

 

[pm_dude 27]

Without the fan it will be a hard print especially with the number of supports.

Bare the bad print quality until you print one full mount, install it and print it again with the fan mounted.

[printerfan 5]

Those prints are attempted fan shrouds, so the quality is so bad I can't even print a print shroud. In addition, one of those attempts above was ABS, my understanding is that fans should be off during ABS, so the lack of fan shouldn't effect the ABS print quality. There is a deeper issue that I need help resolving, so I can print the shroud.

 

[pm_dude 27]

You say the abs print stopped extruding filament. Did the filament grind at the feeder? I have seen a few ABS brand that are too big and sometimes get stuck in the bowden tube because they get over 3mm diameter.

Why did you set the extrusion to 200% on the 0.08mm print? That is clearly an issue. 210C was most probably too high for that print. 195C would probably work if the nozzle is in good shape.

The last PLA print, why did you stop it? Was there a real problem preventing you from continuing? Is it 0.2 or 0.3 layer height (the description on the image say 0.2mm). Try reducing the temp slowly. As long as its not under extruding you'll be fine.

There is no point in aiming for a good quality print at the moment. At least not with PLA.

As for the ABS I have not used it enough to give you good advice on how to use it but I would be temped to say that the bed at 205C is over the top. Probably 110C would be enough. You need to make sure the build area is as closed as possible to keep the heat inside and prevent cold air from going in. At least put something to close the front opening. It will help layer bounding.

 

[printerfan 5]

Sorry, the bed for ABS was 105C, not 205C that was a typo (now corrected). My bed has difficulty reaching 110, it stalls around 107-108C even after 25 minutes of heating. The room temperature may be an issue for the ABS, my room temperature is 56 F. I will finish building my enclosure this week.

Here is the latest PLA print of the fan shroud:

PLA, .2 Layer height, 30 mm/s print speed, 220C nozzle, 50C bed, 100% extrusion, shell thickness .08, Brim turned off, Support type: Touching Build Plate on

 

The shroud was printed on its side and this is the top. The final portion did not print, also the supports were very difficult to remove and I ended up breaking a hole in the print trying to remove the supports. Shell thickness .08, should I increase shell thickness?

 

[printerfan 5]

I ultimakely want the shroud printed in ABS because I have read on the forums that PLA shrouds deform over time and will contact and damage prints.

The ABS had very little friction when freely pulled through the bowden tube and there was no grinding.

 

[pm_dude 27]

Grid support is always more difficult to remove than line support but line support are also weaker and break more easily during the print. You can change the support type in the expert settings in Cura.

In addition to difficult to remove grid support the fact of not having fan (PLA or ABS) also mean that supports are more likely to fuse with the model. This happens a lot to me when printing XT.

I might not see the shroud properly but could it be printed standing like in the first picture without any supports?

Whats missing on the print? What part did not print?

Is it usable as it is? Can you patch the hole and install it just for the sake of printing another one?

For PLA and ABS close to the nozzle you can place some aluminium around the section. Use a section of a coke/beer can or some layers of aluminium paper folded one over the other.

 

[printerfan 5]

PMdude

After looking at the shroud again, nothing is missing on the print.

I reprinted the shroud at .1 mm, but kept all the other settings the same. The results: Exact same quality. So I decided to attach the new undamaged shroud to the printer.

With the undamaged shroud attached to the printer, I printed a third shroud (also in PLA) hoping the cooling fan would improve the quality. The result: EXACT same quality. It does not appear that the fan improved anything. One odd thing I did notice though was that although I put 100% fan in Cura, when I look at the fan setting on my printer it says 255.

Why is the fan shroud not improving the print quality? Do I need to tweak a setting?

 

[pm_dude 27]

Can you post a picture of the latest shroud just to see?

From the previous pictures I see under extrusion or small holes on the shell. If these are holes they could be caused by the head movement between the inner shell and the outer shell. They are usually bigger the bigger the layer height . At 0.1mm layers you shouldn't see them. If its under extrusion the next comment will make it worst.

At 0.1mm layers and 30mm/s you could easily print at 200C or even less. What filament brand do you use? Some could require higher or lower temp.

I also see a lot of stringing (drips of plastic caused by retraction). Stringing happen more when the nozzle is hot but depending on the speed it may be needed. If you print hot you may want to play with a few retraction parameters and also with travel speed. Higher travel speed will spend less time moving without printing. Longer retractions should help reduce the strings.

The fans at 255 = 100%. Fans will have an impact on

 

[printerfan 5]

I terminated the third shroud print prematurely because it looked like the exact same quality as before, but I can post the picture of the partial piece if you want. I wondered if it was just the nature of the shroud model, so I printed another Ultibot, since I have a few to compare it to.

The brand I am using is Protoparadigm PLA.

My travel speed is 150 mm/s. Should I alter my travel speed and retraction settings? Are the pictures below showing underextrusion?

Here is the latest print using the mounted shroud (used supports this time, can compare to ultibot prints on previous page).

Protoparadigm Brand PLA, .1 Layer height, 30 mm/s print speed, 220C nozzle, 70C bed, 100% extrusion, shell thickness .08, Brim turned off, Support type: Touching Build Plate on

 

[pm_dude 27]

For this print you need no support. The supports for the hand are the only one that are needed so turn off the supports touching the buildplate.

I would like to see a shot of the base of the ears as they will show most of the effect of having good fan cooling. (Watch out with the focus. You better stay further from the object to get good focus)

If we compare with the old pictures you posted its getting better (ignoring the hand issue)

Try the same print with lower temps. Try at 210C, 200C and 190C-195C. The colder you will print the better overhang will get and the less strings you will get too.

The top antenna are bad because you need to use cool head lift option or print more than one at the time. You can see some more info here:

http://umforum.ultimaker.com/index.php?/topic/8993-globular-final-10mm/

 

[printerfan 5]

The resolution including the antenna looks better in the older prints (fan off), but the overhangs are much reduced in the newer print (fan on).

Fan On

 

Fan OFF

 

Fan ON( left) Fan OFF (right)

 

[pm_dude 27]

Did you look at the pictures before posting them? They are all out of focus.

I explained already why the antenna look bad.

 

[printerfan 5]

Sorry, I tried to take them as best I could, this was the best focus I could get at that distance. I can stand further back, but I'm afraid it may not capture the detail you want to see.

i will try another print with the cool head lift on my next print and take pictures at a further distance.

I have dual extrusion, but the extuder I usually use now appears unable to get filament into the PEEK insulator. I disassembled the print head and it looks like the PEEK is clean as is the nozzle, so im not sure why the filament is not feeding into it properly.