Problem with a large print (failure and quality issues)

[bez 9]

I attempted my first big print today but it ended in what I can presume was a nozzle blockage as PLA has stopped being extruded. As I came back to check on it and it was printing above the surface of the print with no material being ejected.

To say I was gutted would be an understatement. I was really looking forward to seeing the end result too.

I'm not entirely sure why this happened but I'm hoping if I post up some pics and the settings I have used someone might be able to shed some light on what might have gone wrong.

I have also noticed some quality issues with the print so some pointers on how to tidy that up would be much appreciated

Settings

Filament = Gold 2.85mm filament from ultimaker (gold was supplied with the kit)

Settings Used

Print thickness = 0.2mm

Shell Thickness = 0.8mm

Bottom/Top Thickness 0.6mm

Fill Density = 25%

Enable Retraction

Retraction settings

Length - 5.5mm

Speed 30mm/sec

Nozzle size = 0.4mm

Initial layer thickness = 0.3

Travel speed = 50 mm/s

Bottom layer speed = 20mm/s

Minimal layer time = 5 seconds

Enable cooling fan = yes

I hope there is a glaringly obvious solution I'm missing or I have overlooked a setting somewhere.

 

[illuminarti 17]

Rather than a nozzle blockage, you may just have ground away the filament in the extruder, to the point where it could not grip it any more.

There are couple of things that you might try... firstly, slightly increasing the tension setting in the extruder - turn the adjustment screw anticlockwise to lower the white indicator piece down a little bit, and try again.

It may have been the retractions for all the infill that caused the problem; what do you have for your retraction settings in the expert settings panel?

Other things that I notice looking at your settings - firstly, the travel speed should be a lot higher - I generally use 250mm/s. And the top/bottom thickness should be a higher multiple of your layer height; you generally want at least 5 layers - so 1mm for a 0.2mm layer height.

 

[bez 9]

Well it had chewed the life out of the filament. I even had a fight with it removing it.

Here is a screenshot of the expert settings, I hadn't found those previously ...... (hangs head in shame)

Thanks for your advice its much appreciated ........... Its a dark art configuring the printer but I must admit I am enjoying it (even the frustrating moments)

 

[illuminarti 17]

Sorry, the photo thing didn't work. Here's how to add photos in the forum....

http://umforum.ultimaker.com/index.php?/topic/4525-how-to-upload-an-image-to-the-forum/

 

[bez 9]

hmmm thats odd. I admin another forum that uses this forum software so I'm pretty confident i linked it correctly. It might just be photobucket having a senior moment.

Here is the url for the image : http://i650.photobucket.com/albums/uu227/MrLEM/expertsettings_zpsd8180ace.jpg

Edit: Did the pictures in the opening post show up properly?

 

[illuminarti 17]

Same 'incorrect link' gif.

 

[bez 9]

Same 'incorrect link' gif.

 

ahhhh thats frustrating. I've uploaded one to the forum:

I hope this one works lol

 

[illuminarti 17]

Yes, the first one showed up now.

With those retraction settings (specifically 'enable combing') it shouldn't be retracting very much, so I doubt the retraction was the issue. It's possible there was just a bad spot on the filament, that might have gotten snagged in the Bowden tube. Or perhaps there really is some sort of blockage in the head - although I'm generally skeptical of that explanation.

Cut off the damaged filament and reinsert it, and see if it now extrudes ok. If so, try printing again. There's a good chance that it will work fine this time.

(One other thought - is the fan on the back of your print head running all the time?)

 

[bez 9]

Since having the issue I have managed to print 3 25mm cubes with no massive issues, so perhaps it was just one of those things?

I have noticed on a couple of the prints the head leaves the print area and returns to home then appears to reset the level of the printer then finishes the print. Is this normal or is it pointing to a potential problem?

If you look at the pictures of the print some of the print about a inch from the base is glossy then the rest is more mat in appearance and it gets a bit "stringy" is there any reason for that?

Sorry for all the questions but as I'm new to all this everything is a new experience and I'm keen to learn as much as possible to help me produce good quality prints.

 

[gr5 1,447]

I have noticed on a couple of the prints the head leaves the print area and returns to home then appears to reset the level of the printer then finishes the print. Is this normal or is it pointing to a potential problem?

What?? Strange. That doesn't sound right. I can think of two causes:

1) Are you printing through USB? If so that would explain both your problems (grinding and strange behavior). USB is not officially supported because you get so many errors that occasionally the checksum matches and it does a wild move.

2) Click on the "plugin" tab in Cura and make sure you don't have the "pause at Z" plugin enabled.

No ideas about the glossy versus matt. Usually temperature affects that. Maybe your fan doesn't come on until one inch up?

 

[bez 9]

Yeah it was odd behavior, it happened a couple of times then went away by its self with no intervention by myself. I've only ever printed via SD card.

I think a strong draft from a door caused the print to fail, if that could be a cause? Also I really don't like the quality of the "gold" PLA that was supplied with the machine ...... thank god I ordered some orange PLA as it prints sooooo much better.

Again, thanks for your kind words of wisdom. Over time there will be less "I'm having problems" threads and more "look what I've made" ones