PLA printing problem

[Gadzhev 1]

Greetings!

I've been having issues printing on an Ultimaker 3 Extended. The PLA nozzle stops printing after several minutes within the start of the printing process.

I've tried hot & cold pulls multiple times, changing the feeder pressure force, manually reducing the temperature of the core, but it didn't solve the issue. So I changed the print core with a spare AA one. It did one print successfully, and then the same issue occurred. It also clogs itself within the first several minutes. 

The attached photo shows what the material looks like in the print core, when the clogging occurs and I unload the PLA. 

Now, with the new print core, I am leaving everything as it is suggested by the Cura recommended profile. Only the pressure force on the feeder is set to between the mid point and top-most position - hence, a little "loosened". Any suggestions as to where the problem might come from?

[gr5 2,189]

One common cause of "printing stops after 5 to 30 minutes" is the front fan being broken.  Make sure it spins as soon as the core gets above about 60C.

 

Another common cause is brittle filament - what happens is the filament cracks and breaks inside the bowden and you get many pieces of filament in there and when the crack gets to one of a few thresholds it gets stuck.

 

Another cause is that you are printing too much filament into too small a space and overextruding the first layer greatly and eventually the feeder grinds up the filament at the feeder so much you get like a bite out of the filament and it stops feeding the filament. 

 

#2 and #3 are obvious if you remove the filament and check to see if #2 it is in pieces or #3 there is a big bite out of the filament somewhere.

 

Another cause is high air temperature.  Like 30C or 85F room temperature and potentially even hotter inside the printer.  Do you have a cover on top of the printer?  If you are printing PLA and you have the AM the fan should be on all the time.

[Gadzhev 1]

On 3/22/2022 at 4:22 PM, gr5 said:

One common cause of "printing stops after 5 to 30 minutes" is the front fan being broken.  Make sure it spins as soon as the core gets above about 60C.

 

Another common cause is brittle filament - what happens is the filament cracks and breaks inside the bowden and you get many pieces of filament in there and when the crack gets to one of a few thresholds it gets stuck.

 

Another cause is that you are printing too much filament into too small a space and overextruding the first layer greatly and eventually the feeder grinds up the filament at the feeder so much you get like a bite out of the filament and it stops feeding the filament. 

 

#2 and #3 are obvious if you remove the filament and check to see if #2 it is in pieces or #3 there is a big bite out of the filament somewhere.

 

Another cause is high air temperature.  Like 30C or 85F room temperature and potentially even hotter inside the printer.  Do you have a cover on top of the printer?  If you are printing PLA and you have the AM the fan should be on all the time.

Hi, thanks for the response.

The material is OK, no cracks. An AC unit is constantly turned on in the room where the printer is, to keep cool temperature and low humidity. We used to have a custom top cover and door for the printer body, but we removed them due to noticeable increase in the temperature within the then enclosed printing area. 

No feeder grinding has been spotted whatsoever, the feeder actually pushes the bowden tube out of the clips. That's how I noticed that something is wrong.

So the problem has to be somewhere in the print head, most probably the fan, like you mentioned. I'll have a look at it and leave an update here.

[Gadzhev 1]

Update on this case:

- I manually increased the temperature of the print core to 60 degrees Celsius and the fan started spinning instantly.
- The printer managed to work for a little longer this time, and temperatures seemed normal for the PLA, but it got clogged and started pushing the bowden tube out of the feeder clips once again.
 

[Icemandad 0]

Thanks Gadzhev. I have been researching a bit and have been having a lot more success with extruding at 215 and heating the bed to 65. very few problems now. thanks again