Plug of PLA in clear pipe - help!

[r0cha 0]

Our Ultimaker has formed a plug of PLA about 3cm above the hot end of the clear pipe. Heating the machine to try and liquify the ply of PLA didn't work and when I tried to pull out the PLA from the reel end it snapped off at the other end of the clear pipe. I now have above 5mm of PLA showing at the reel end of the pipe and non at the hot end.

I need help!

If I cut off the clear pipe above the plug of PLA will the shortened clear pipe still be usable, or will it cause other issues?

Any other suggestions much appreciated.

Photo below.

 

 

 

[IRobertI 469]

I would try heating the tube to soften the PLA. Try dipping the clogged end into boiling water and see if that helps. Using some sort of pushing rod would likely help in getting it moving. If that doesn't work, maybe try heating the hole thing up gently in an oven (or a big bucket of water so you don't have to bend the tube too much). PLA starts getting soft around 60C or so.

Only as a last resort would I cut the bowden. Taking a couple of cm off it wont hurt but if it can be avoided that's a better option.

 

[gr5 1,471]

Please go to "gallery" in the top left corner of this page and upload the picture. Then post a new message in this forum and click on "my media" next to the smiley face and select that uploaded image. Thanks!

The "clear tube" is called the bowden. Did you remove the bowden from either end yet? I need to see the photo but I'm guessing you can't do much until you do that. I guess you'll have to remove it from the print head - remove the blue clip, push down hard on the outer ring and pull up on the bowden. You should have the print head at 180C when you do this so that you aren't fighting with the plug also. Then once that is off you can use hot water as Robert says.

 

[r0cha 0]

Thank you for your help, much appreciated. Back in action after a little surgery on the Bowden.

 

[IRobertI 469]

For the benefit of others who come across the thread in the future, which method worked for you?

 

[donidu 0]

Hi,

I would like to know if you had the problem with the PLA-plug in the bowden tube with an ultimaker 1 or with the ultimaker 2?

I am having the same issue with an ultimaker 2: About 1 cm of the PLA-Filament showing to the hot end seems to be butted or swollen. Unfortunately I damaged the bowden tube when I unsuccessfully tried to get the filament out with a pliers and a rod, so my printer is out of operation now .-(.

It happend when I printed an object with the minimum layer height and I wonder if the slower material feed could have caused that the filament became weak at some distance from the hot end because it had more time to heat up?

Tom

 

[gr5 1,471]

It's certainly possible.

Actually any time you have retraction, if you think about it, you are sliding PLA upwards which also brings heat upwards. The warm/hot PLA is moving up to a cooler section of the print head and transferring some heat up there. then it goes back down and *now* the part of the print head just warmed up heats the higher up PLA and on the *next* retraction you transfer the heat higher up again. Only a little heat is transferred each time. But that 3rd fan should help prevent this from getting to severe.

More likely in my opinion is that the 3rd fan on the print head is broken. I'm pretty sure it should always be spinning when you heat up the nozzle. The purpose of that is to keep the nylon pieces from melting and also to keep heat from getting up towards the top of the print head assembly.

 

[donidu 0]

Thanks for the hint conderning the third fan. I am going to check this when my printer is working again. I hope to receive the replacement bowden tube before the weekend and I'll see if I manage to get everything in place again.

 

[donidu 0]

...

More likely in my opinion is that the 3rd fan on the print head is broken. I'm pretty sure it should always be spinning when you heat up the nozzle. The purpose of that is to keep the nylon pieces from melting and also to keep heat from getting up towards the top of the print head assembly.

When I replace the bowden tube which was damaged when I tired to remove the plug, I found also the probable cause of the problem. When I followed a loose wire in the printhead I found that it leads to the third fan. So your assumption was right. The fan on the reverse side was not connected and hopefully the problem is fixed now forever.