Cannot Print PLA :-/ Tried almost every Idea found on web

[dimitrisFeelform 1]

It's my first post in this forum so hello to everyone.

I have this problem for one year now and it makes really frustrated and tried almost everything which makes it unexplainable ( I have read almost everything online for troubleshooting) . I cannot print with PLA not matter what. Lets take it one by one.

I cannot print with PLA not matter what - I have underextrusion and even if I press the filament by hand it seems resisting.

I can print ABS succesfully (very good quality prints) though no matter what the quality of it.

Tried different speeds, temperatures and multiple PLA producers and still no solution

Did the atomic method million times ... the nozzle is totally clean

So what is the problem?

[valcrow 144]

How old is your printer and how long have you been printing with it? If you feel excess resistance pushing the filament through by hand it's likely caused by the PTFE coupler. That needs to be changed out every once in a while. And the usual symptom is under extrusion to non-extrusion after about 10 layers.

If you could post a picture of your failed prints this will also help diagnose.

[Dim3nsioneer 557]

Might be the PT100...

[dimitrisFeelform 1]

How old is your printer and how long have you been printing with it? If you feel excess resistance pushing the filament through by hand it's likely caused by the PTFE coupler. That needs to be changed out every once in a while. And the usual symptom is under extrusion to non-extrusion after about 10 layers.

If you could post a picture of your failed prints this will also help diagnose.

 

Thank you for your answer my printer is 2 years old. I would say that my total printing time is something around 400 - 500 hours, problem started something around 300 hours of printing.

I will provide you with the appropriate photos when I return home ;-).

Only one question if it is the PTFE coupler why does it print birlliantly in ABS ?

[dimitrisFeelform 1]

Might be the PT100...

 

Why do you think it could be the sensor?

[DidierKlein 729]

What is the brand and size of the PLA you are using?

Have you tried printing a little hotter? (like 220°c)

[dimitrisFeelform 1]

What is the brand and size of the PLA you are using?

Have you tried printing a little hotter? (like 220°c)

 

FABERDASHERY PLA, plastic2print PLA, cheap chinese ebay PLA. All of it behaves more or less the same. I tried to increase temperature but it only makes it better for just some minutes. I am experiencing considerable underextrusion. It is still mind boggling why ABS prints just fine.

[Labern 774]

The PTFE effects PLA more then ABS. I would think that it will need replacing with that many hours of printing with ABS if you want to use PLA.

You will also need to do a lot of atomic pulls to make sure all the abs is cleared from the nozzle before using PLA. If you don't do atomic pulls the at the lower pla temps it won't clear naturally.

[eldrick 65]

To determine whether it is the coupler, remove it and inspect. If it isn't smooth and clear inside the hole, use a 1/8" drill bit and open it up. Replace.

If the coupler was the issue, you just solved the problem temporarily (then buy a new coupler or two).

[valcrow 144]

 

How old is your printer and how long have you been printing with it? If you feel excess resistance pushing the filament through by hand it's likely caused by the PTFE coupler. That needs to be changed out every once in a while. And the usual symptom is under extrusion to non-extrusion after about 10 layers.

If you could post a picture of your failed prints this will also help diagnose.

 

Thank you for your answer my printer is 2 years old. I would say that my total printing time is something around 400 - 500 hours, problem started something around 300 hours of printing.

I will provide you with the appropriate photos when I return home ;-).

Only one question if it is the PTFE coupler why does it print birlliantly in ABS ?

 

2 yrs and 500 hrs it is likely the PTFE is the culprit. 2 years ago, I'm nots ure if they started including a hot end pack with the printer, but check to see if you have an extra PTFE in your box and install it if you do. Otherwise, get a PTFE and it should solve your issues.

The problem with the PTFE is it develops a cavity near where it touches the brass. It seems like when it retracts, the hot PLA goes into the PTFE and expands outwards into the cavity when the retraction rolls the filament forward. This blob eventually hardens or enough pressure is built that it isn't able to push filament down more. You can also see this when you do an atomic pull and it snaps or stretches with a small blob at the end.

Here's a picture of some deformed PTFE's I sliced through.

@Eldrick I tried drilling out PTFE's back in the day when I thought there was a lip that was formed preventing the extrusion, but this only helps for a few more prints, the cavity is what I find is the cause of all the printing woes.

If you do buy a PTFE, get the new teflon ones used in the +'s those are awesome and last a lot longer.