Working w. ABS but not w. PLA

[fxmouton 0]

Hello everybody,

I've got another issue with my Ultimaker and I have not idea why I do have this issue.

I printed something with red ABS filament and it worked perfectly. But I needed to print other stuff in PLA. I have two bobins :

 

• Orange PLA filament, I received with my printer so it's from Ultimaker and it's usually working
  
• Blue PLA filament, from esun (esunchin.com) which is quite bad quality and I've got problems time to time.
  

None of them seems to work anymore! Everytime, I've got some feeding issue and it's giving me this kind of results :

I didn't change any setting. It worked with ABS, then I put PLA. PLA didn't work so I put back ABS then it worked again and fail again with PLA. When I go to the "Move Material" option, the PLA pops out the nozzle. I have no idea why it does that.

Any thought?

Thank you!

 

[shurik 87]

Bonjour fxmouton,

Did you change the material settings on the printer to PLA? The PLA pops because at 260C, it is too hot for it, so it literally boils which can lead to blockages in the printhead due to burnt plastic residue.

I would check the settings and just in case, clean the nozzle.

Cheers

 

[fxmouton 0]

Yes I automatically use "PLA" presets of the machine, but yes I didn't think about cleaning the nozzle. I'll try this and I'll let you know.

Thanks!

 

[yellowshark 153]

Yes the most likely problem. If you are not familiar with the Atomic method, then search this forum on Atomic. The posting is for PLA but if you have ABS stuck in the nozzle you will have to raise the temperatures and use ABS to do the pull (I think - someone may want to correct me). I guess heat to 235/240, feed 40 /50mm of filament then reduce temp to 160/170 and pull. Again someone more knowledgeable than I on ABS may want to correct those suggested temps.

 

[fxmouton 0]

I tried with the different temperatures, with ABS and PLA and I think I made the things worst now. I did it like 20 times, and nothing seems to go out the nozzle. Is it normal I had to do it that much for no visible result?

Maybe I do it wrong, I don't really know what is the better way to clean it, il PLA works bette than ABS to clean the whole thing. I saw alors the http://umforum.ultimaker.com/index.php?/topic/9928-korneels-method-for-cleaning-hot-ends-um2/?hl=atomic, but I won't be able to do it at my work place (the printer is not mine, it is the one of the office).

Thanks anyway,

 

[korneel 176]

yay! i finally have my name attached to something

i would recommend you find some Taulman Nylon.

heat up the nozzle to 260 degrees, wait a minute or so, then start feeding in the nylon. please note that you would need to do this through the bowden tube or cut off a piece of bowden tube since nylon is very flexibel. you can try without a bowden tube but it's very hard to do so.

keep pushing untill it either comes out or you cant push it any further. dial back the temperature till 30 degrees and keep pressure on the Nylon.

once the temperature is below 170 you can leave the nylon be and wait til the temperature drops. leave it ike that for a minute or so then raise the temperature till 140. at 90 degrees start pulling the nylon (don't damage the slider bars!) and you'll see it pop out at around 110 degrees with a lot of black stuff attached to it.

keep repeating this process untill it's clean..

you can find some more info around this at www.korneel.nl

 

[fxmouton 0]

Unfortunately, I don't have this Nylon (yet). But I'll keep this in mind, the next bobbin of filament I get might be this one. I was quite in a hurry so I use another technique (should I call it the Francois Technique? :-P )

I unmounted the nozzle, but I keep it connected with the computer of the Ultimaker. Why? Because I don't have tool with the EXACT size of the screw which keeps the wires connected.

Anyway, I hold the nozzle with some pliers and with the help of a screwdriver and a pin, I itch the material to remove it. When it's hard, I heat up the nozzle (up to 260 if ABS) so I can empty the rest of the material.

Following the mounting of the print head, I do the atomic method couple of times to be sure there is no more residue left inside the nozzle.

I really feel like MacGyver sometimes, but who doesn't when you've got a 3D printer :mrgreen:

 

But THANK YOU GUYS! I started to print something and it seems to work quite alright! You were right