What do you think is the cause of the material looking like this?

[lukassvensson 0]

Hi! 

 

I would greatly appreciate if anyone can give their input on what could have caused this. I printed using my red material (PLA 2.85 mm) in an Ultimaker 3 and it completely jammed the machine after two prints. I had a lot of projects to do so I started using another printer (an Ultimaker 2) and it worked fine until I used the same spool of red material and the Ultimaker 2 got jammed the exact same way (nothing came out of the printhead).

 

I then suspected it might be the material and I looked how the now jammed material looked, and I noticed small dimples accross where the material had been fed into the machine, as well as two giant indentations that the wheels of the feeder must have dug into the material. Is it possible that this material is too old and this causes it to break when the machine is handling it? I read that PLA has a shelf life of 2-3 years. 

 

Thanks for any input! 

[lukassvensson 0]

I took a closer look at the feeder and it's full of crumbled plastic. This leads me to believe the PLA-plastic was old or dried out. Do you think this is a correct guess? 

[lukassvensson 0]

The material is completely stuck in the tube, I can also feel it's brittle, so I suspect the material has been improperly stored. 

[Enigma_M4 75]

Hi,

it might be off topic, but your feeder is assembled wrong.

the head of the set screw for the feeder tension must be inside the feeder housing, your's seem to be outside.

That for the feeder tension is incorrect, the indicator normally is placed mid-scale.

Regards

[Enigma_M4 75]

actual video to this topic by CNC Kitchen:

 

[lukassvensson 0]

On 5/6/2022 at 7:14 PM, Enigma_M4 said:

Hi,

it might be off topic, but your feeder is assembled wrong.

the head of the set screw for the feeder tension must be inside the feeder housing, your's seem to be outside.

That for the feeder tension is incorrect, the indicator normally is placed mid-scale.

Regards

 

Thanks for both your posts. This issue occured with other filaments too, so it's probably that the feeder is set to feed too tight, so that it ground down the filament instead of feeding it. I will attempt to decrease the tension that the feeder gives. 

 

I found this guide on how to do it: 

https://support.ultimaker.com/hc/en-us/articles/360012015880-Material-is-ground-down-by-the-feeder

 

I will update how it went after I'm done. 

[lukassvensson 0]

Now that I've taken a closer look, it doesn't seem possible to adjust the feeder tension. The screw on top of the feeder doesn't do anything, it just comes loose if you screw it. I see on the white indicators that the feeder is set to max pressure, which would explain why the material is ground down, but how do I decrease the pressure? 

 

Thanks for your answers! 

[lukassvensson 0]

This is what the manual for the printer says to do, but I am unable to do this. As you can see there's a screw in the hole that you are supposed to use to adjusting the the tension. When I remove the screw there's nothing to grip in the hole to adjust the tension. I am starting to think what you said Enigma_M4, that the feeder is somehow put together wrong, is the cause of this issue. 

[lukassvensson 0]

Here is two more photos of what it's like when I've removed the screw. As you can see, I can insert the entire screwdriver and there is nothing there. Does this mean the feeder is assembled wrong? 

[Enigma_M4 75]

As I wrote in my first post, the set screw is the culprit.

At your feeder, the head of this screw is exposed outside the feeder housing.

But this screw head must be INSIDE the feeder, just below the hole it's sticking out, as seen on the foto of your manual:

 

If this screw is positioned right, it's supported by the top of the feeder housing and screwing it "out" will increase feeder tension, meaning the indicator going down. Your actual feeder tension is zero.

[Enigma_M4 75]

See this foto:

http://4.bp.blogspot.com/-f1ZVlOl_YcY/UuoslXKMBGI/AAAAAAAADhU/aeLFzASDtCQ/s1600/IMG_5787.JPG

Regards

[lukassvensson 0]

25 minutes ago, Enigma_M4 said:

See this foto:

http://4.bp.blogspot.com/-f1ZVlOl_YcY/UuoslXKMBGI/AAAAAAAADhU/aeLFzASDtCQ/s1600/IMG_5787.JPG

Regards

 

Thank you so much Enigma! I just have one more question, I've been looking at the guide and your photo, and I think I've put everything right. However this one part fell out when I opened the housing and I can't find out where it is supposed to go. 

[Enigma_M4 75]

This little metal collet belongs where the filament enters the feeder housing. the larger part looking down (outside the housing), the smaller part up.

[lukassvensson 0]

10 minutes ago, Enigma_M4 said:

This little metal collet belongs where the filament enters the feeder housing. the larger part looking down (outside the housing), the smaller part up.

Thank you sooo much! I got it back together, and before I use it again I just want to ask so I'm 100 % sure. The feeder can now be adjusted. Am I supposed to put it in the middle or at the top? 

[Enigma_M4 75]

For the UM2+ / UM3-feeder and newer, the middle position is told to be the best, and as the UM2 feeder is very close to the UM3, I'd say try middle position. Light markings on the filament show good tension. If the markings are very deep, reduce tension (scale: up), if it's grinding the filament (like your starting problem), the tension might be too lose, referring to CNC Kitchen's video.

Regards

[lukassvensson 0]

53 minutes ago, Enigma_M4 said:

For the UM2+ / UM3-feeder and newer, the middle position is told to be the best, and as the UM2 feeder is very close to the UM3, I'd say try middle position. Light markings on the filament show good tension. If the markings are very deep, reduce tension (scale: up), if it's grinding the filament (like your starting problem), the tension might be too lose, referring to CNC Kitchen's video.

Regards

 

Now as soon at the material is fed all the way the feeder is just jacking, unable to feed it through the printhead. I have tried the atomic method to get rid of some filament that was in the printhead, so it's not blocked. Do you think this is a separate issue, or is it caused by too lose tension? 

 

I should explain more in depth, the feeder does accept the material with some help, then it gets to the print head, at which point it stops revolving, and instead makes a jacking motion. It's like the feeder is too weak to properly feed the material anymore. 

Edited Monday at 09:26 AM by lukassvensson

[Enigma_M4 75]

The upper end of the scale is least tension, the lower end is most tension. the plug with the indicator sits ontop of the tension spring and is pushed down against this spring by the set screw.

What do you mean with jacking? Is the stepper motor skipping (this would be a sign of to much tension), or is the filament slipping (to little tension)?

Do the markings on the filament look like this?

https://support.ultimaker.com/hc/en-us/articles/360012112759-The-feeder-of-my-Ultimaker-2-go-extended-is-ticking-back-skipping

As I'm getting at my wit's end, adjusting the tension gradually to the point where the filament is extruded through the nozzle and the feeder has a good grip is the only thing I can suggest.

Regards

[lukassvensson 0]

7 minutes ago, Enigma_M4 said:

The upper end of the scale is least tension, the lower end is most tension. the plug with the indicator sits ontop of the tension spring and is pushed down against this spring by the set screw.

What do you mean with jacking? Is the stepper motor skipping (this would be a sign of to much tension), or is the filament slipping (to little tension)?

Do the markings on the filament look like this?

https://support.ultimaker.com/hc/en-us/articles/360012112759-The-feeder-of-my-Ultimaker-2-go-extended-is-ticking-back-skipping

As I'm getting at my wit's end, adjusting the tension gradually to the point where the filament is extruded through the nozzle and the feeder has a good grip is the only thing I can suggest.

Regards

 

Yes, exactly. The motor is skipping. I put the tension on the minimum, but it still skipped. Now the material wouldn't even eject from the feeder. I will probably give up on this printer and just assume the feeder is broken. Thank you so much for your time and expertise!  

[tomnagel 89]

It sounds like you are almost there. You can remove the bowden tube at both ends and test 2 things:

1) how much force is needed to extrude filament when you push it in on the top of the printhead manually? Should be roughly around 10N

2) if the feeder is feeding the filament, it should be able to push with roughly 20N (because up to roughly half of the force is lost in the tube)

 

if your extrusion isn’t working, I suspect one of the two is wrong. 
(and I hope you have all settings in Cura default)