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olivierc

Can't print with Ultimaker's red PLA, what am I doing wrong?

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This is going to sound dumb, but I can't print with ultimaker's red PLA, while I have no problem printing with silver, and PLAs from colorfabb.com

I finished building my ultimaker last week and played a bit with it. I printed with the default silver filament with no problem on first try, I was surprised.

Then I switch to a beige filament from Colorfabb, very nice too, in fact looks even better. Tonight I wanted to try to print this http://www.thingiverse.com/thing:12208 and since I had ordered a spool of red PLA with my ultimaker, I decide to switch.

I spent hours, literally hours, trying to print something. The filament would just not extrude, I would just get a couple layers and then it would "air-print". Sometimes it would not even print the first layer. I have been using the same standard settings that I used for my other prints with (almost) no problem : 50mm/s, 0.2mm layer and tried various temperature between 200 and 220°C. Nothing extreme, no high speed or low temperature.

At first I thought the head got clogged, but that was not it, it flows correctly when I raise the temperature. I even disassembled the head for proper cleaning. I removed the filament several times, I tried leveling the bed many times, no luck. I tried playing with settings, different infills values, layer thickness, temperature... I double-checked the filament diameter... nothing worked. I even tried the quick-settings in Cura.

I finally gave up after 4 hours (yeah really), and AS SOON AS I SWITCHED BACK TO ANOTHER FILAMENT, IT WORKED JUST FINE! the same gcode, using the same settings, without regenerating it, worked just fine on first try, at 220°

So is there something I don't know? does the red PLA from ultimaker requires special skills? Or did I get some ABS by mistake? Label says PLA but I noticed my other filaments are all soft while this one has some texture on it.

Also, while I'm here, most of my prints have some under-extrusion, but only on a couple random layers. The whole object looks good, except for one line in the middle. I know under extrusion happens when you try to print too fast or/and at too low temperature, but I have been very reasonable, always at 50mm/s and never under 200. I don't mess with temperature or speed while I print and the filament diameter seems quite constant. And it even happens on test cubes, so it's not related to the object. Does anyone know what can cause random under-extrusion in the middle of an otherwise good print?

 

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Hello, often i must clean the nozzle by changing colors (grff perlsilver (220°) to multec neongreen 240°, ....) grff perlsilver crystallized by high temp and multec neongreen is tough by 220°.

Unscrew the noozle and use a blowtorch to burn out the nozzle for 30sec. Use a needle to pull out little stuff. Burn out 30-60sec. Now you can print with red color. All waste and crystals are destroyed :) It works fine, no air and wool prints.

 

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Thank you for the replies. the smell is not really different, so I guess it's PLA, I heard ABS smelled really bad and it did not bother me. I did measure the thickness at random spots and it varies between 2.81 and 2.9 so I set the diameter to 2.85.

I did feel that I could more easily push the filament when I heated over 230, but I was worried about using such high temperature for PLA as every one say they don't go over 220. So I'll try that next time. And the nozzle is not clogged, I have been printing very well after that using other filament, it's doing a nice long print right know and it looks really good. But thanks for the tip, I don't have a blowtorch, maybe I'll get one some day

 

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I have Ultimaker red PLA that I ordered on August 28th, 2012 with this designation:

"PLA plastic - Red 0.75 kg PLA_RED_075"

Sometimes it would print nice, but over time is was unreliable, I think that the diameter is not consistent.

I have some left on the roll but I don't use it anymore.

Ultimaking unfortunately does not have a good Quality Assurance process for their PLA. Some rolls are really great (like a green translucent I have) but for me it's more important that I can trust the PLA consistency / quality. There are enough parameters to tweak for good prints so I definitely don't want to have uncertainty over a roll....

Nowadays I only order from Colorfabb or Faberdashery, so far all of their filament has proven to be really good. I'm located in Europe / Sweden so they are the best for me so far I think.

I would report your roll as bad and try to get a new one...

/Daniel

 

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printbl.com is good quality in usa.

Regarding temp: When I don't have to worry about stringing, I always prefer to print hot and fast. I've printed dozens of parts at 240C - mostly large parts. At 240C I've had some success even printing at 200mm/sec and .2mm layers which should be impossible for the feeder but it works. But retraction basically doesn't work at 240C and you get lots of stringing if you have gaps that the nozzle goes over. But for something like a large 5 inch diameter gear - 240C is great.

But usually I print at 190C.

 

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Thanks for the replies. It's PLA, I did the bending test. I tried printing at 240 with it and it seams to work better this time. Now I know that if it does not print when it should, it's not necessarily because it's clogged but just because it's not hot enough.

But I still have the random under-extruction problem, it just ruined a 5 hours print this weekend

 

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If you are having extrusion problems, you might want to check the material feeder. This part:

http://www.flickr.com/photos/ultimaker/8635151612/

We had a few machines here at UM which had occasional extrusion problems. I did some full diagnostics, and I found that on 1 machine the bearing in the wheel was not properly centered causing the wheel to be pushed sidewards.

But the other issue gave move problems, the long bolt that you see there, with the lock nut, it was screwed on tightly, so the side plates (not seen in the above photo) where clamped on the side of the feeder, making it unable to move.

This is quite easy to check, if you lock/unlock the filament feeder (by lowering/raising the lever) you should be able to see the clamp move. But the clamp and the spring part should move a different amount, if they move the same amount then the spring part isn't working.

 

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Ok, the bearing was not very well centered, I remember having a really hard time inserting it, so I thought "good enough". I managed to push it a bit more to the center. I unenlightened the clamp too, we'll see how it work. Thank you for the tip.

I printed several parts in red at 240 tonight, it worked very well, even bridges and slight overhangs

 

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