New Ultimaker S3 - need help diagnosing failure

[broseph 1]

Hey there,

 

I've just got my new UMS3 set up.

 

I've had a handful of successful small PLA prints (Benchy etc) but have started printing larger projects (7-8hrs) and I'm getting consistent failures.

The failures happen both with PPVA support and using the PLA for support structures as well.

Here's what's happening:

 

Print seems to kickoff just fine, and I'll watch it for a while, then somewhere down the print something happens to cause the printer to stop extruding.

A couple of times the bowden tube gets pulled out of the feeder on the back of the machine. (I've tried trimming the tube a bit and re-chamfering, and creating a little circlip to help hold the tube in, but that hasn't helped the root cause)

 

When this failure happens I run the print core cleaning wizard, and do a bunch of the hot\cold pulls (using PLA, as I don't have cleaning rods yet)

I've repeated this thorough cleaning and retry many times now, and I get what appears to be a nicely extruding thread coming out of the nozzle.

Then I start the print again and the same event happens.

 

During the last failure: (about 30mins ago) I watched while the print failed.

I was running the part in single material (PLA) and about an hour into the print I saw the end of the nozzle was clearly boogered up.

 

I'm using the two materials that came with the machine:

Ultimaker Tough PLA Black

Ultimaker PVA Natural

 

Print settings are coming from the standard CURA visual settings.

 

I'm new to problem solving this and need some expert help.

Thank you.

 

jg

 

 

 

[Carla_Birch 116]

If the bowdon tube is coming out the feeder itself, then the coupling collet itself might be damaged (most likely the teeth inside that grip the bowdon tube)

 

Without having a spare collet or being able to see any damage next to others, you could try swapping it with another on the printer and then if the bowdon starts to come free at the place you swapped the collet with now then that would make it highly likely its the collet.

 

It's also worth maybe trying another spool of filament, incase you just got a bad spool of PLA. I see you using the cura settings for visual, did you also make sure it was for the tough pla profile and not normal PLA?

[broseph 1]

Hey Carla,

 

Thanks for the reply.

 

Bowden tube: I've got spare collets/ clips/tube on order. in the mean time i've trimmed down the original tube about 5mm and used a makeshift clip to hold the collet tight.

Swapping collets sounds like a good thought if i keep having issues

 

I just ordered another PLA spool as well, this is the only thing i have right now: so I will test that as soon as it shows up.

 

and Yes, I just double-checked. My Cura settings are using the UM Tough PLA specifically.

 

 

[Gero 54]

I had this error once as well. I can confirm that changing the coupling collet fixed it, although I also tried shortening the tube.

[broseph 1]

Hey Gero, 

 

thanks for the experience there.

 

-So I shortened the tube and used a makeshift wire collet-clip to hold-er in there.

 

What I cant tell is: is the collet issue a symptom, or is it the root cause?

Even after installing the makeshift clip I'm still getting clogs (usually on the PLA side).

Photos show the bowden tube popped out, a failed print, and the print head afterword.

 

 

 

[Carbon 28]

Just a thought, Is your base (glass plate) level? Try running the "Manual Level" in Maintenance.

 

Looking at the print cores, it could be that the tip of the cores are too far away / too close to the glass (during print).

 

The bowden tube collets are a bit hit and miss, you're better off looking for a different one on line, we've got the clip that allows the use of a small "zip" tie, which seems to help a lot. 👍

[Gero 54]

I would say the collet issue is the root of the problem. This is the parts with the metal teeth that holds the tube. Sometimes it can help to shorten the tube a bit because it can remove the deep marks on the outside of the tube if there are any. 

 

I had my problem after I changed all tubes and collets on my printer for the "1 year maintenance". This one collet seemed to be a bad one. It didn't happen often or on every print, but from time to time. Changing the collet fixed it for me with no other errors.

[SandervG 1,521]

Hello, it is possible that the collet is the problem. Alternatively to ordering a new collet / tube, your reseller might have been able to ship you a new one if your collet is not working properly. It has 4 metal teeth on the inside which bite into the bowden tube and keep it in place, if they are bent or missing they have less grip and its possible they can't hold the bowden tube in place. 

 

When your collet is fine, but something else created so much force that it pushed your bowden tube out of the collet you could shorten the bowden tube because the area where the collets previously bit into the bowden tube might be scraped, so it will have less grip. You can't endlessly shorten it though, since it will change the inner tension in the bowden tube (curvature) and filament extrusion parameters are calculated with a standard bowden tube length in mind. 

 

Most likely, you just need a new collet (and maybe a new bowden tube?) and that should solve your issues!

[broseph 1]

7 hours ago, SandervG said:

Most likely, you just need a new collet (and maybe a new bowden tube?) and that should solve your issues!

Thank you - I have a new bowden tube and clip on order -hoping this is an easy solve.

 

12 hours ago, Carbon said:

Just a thought, Is your base (glass plate) level? Try running the "Manual Level" in Maintenance.

 

Looking at the print cores, it could be that the tip of the cores are too far away / too close to the glass (during print).

 

I believe it's level, but not sure, I've never run the leveling process. I'll try that. thank you for the idea.

 

 

 

[broseph 1]

Update: 

 

Tried manually leveling the bed, and running a print. Also tried raft instead of Brim on this one.

I trimmed off another 5mm or so where the collet looked to be scarred, and re-installed.

 

Print ran for about 45 minutes when the tube popped out again. 

came back from the store to see a nicely printed raft, and some support material, but the nozzle wasn't extruding and it was way above the bed. 

 

after the abort I released the tension on the feeder and manually fed filament, and the nozzle extruded right away. This leads me to believe that a clog didn't occur. 

 

Hoping the collets and new tube get here quickly and that is the solution.

 a bit of a bummer to have a problem like this at the beginning of the journey, but i suppose I'm learning a lot.

 

thank you for your help so far.

 

Here's what the failed print looked like - maybe there's some evidence here that i can't see:

Edited May 26, 2021 by broseph

[SandervG 1,521]

If your bowden tube pops out, I think there is less resistance for the material to just go free out there in the free world where the tube disconnected, than there is to push through the nozzle. So it makes sense that if this happened, your nozzle stopped extruding. I don't think it makes sense to try again. Did you ever inspect the inside of the collet? Can you see 4 equally sized and angled small metal blades? 

 

If this has happened before, the filament that was sitting in your print core waiting to be extruded before the bowden tube popped out, might have been sitting there for some time being heated and heated. You might want to clean your print cores before you try a new print with new collet + bowden tube, to ensure you are not running into a clog that has been building up from these endeavours. 

[broseph 1]

Thanks SandervG

 

ive run a print core cleaning every time I’ve had a failure because I was under the suspicion that it wasn’t extruding due to a clog. I’ll continue to clean before restarting as well.

 

heres what the collet looks like:

It doesn’t appear to be damaged, but I’m not sure what the proper collet should look like either. 
 

I have a new collet and tube on the way. So I will replace and try again soon.

 

looked like there was some grinding going on as well: when I opened the feeder, there was quite a bit of black PLA dust... not sure if that’s symptomatic of something else or if this collet issue would cause that as well.

 

thanks!

 

jg

[SandervG 1,521]

I must admit, that is a pretty good picture of a collet! 🙂  But it's still quite difficult to say if it is good or not.. at least it seems like it has 4 blades. 

 

Do you have the flow sensor disabled? With the flow sensor enabled, I would suspect that you would get a notification on your machine before it started to grind. 

 

Did you also use the instructions here on how to clean and put the feeder back together?

[Smithy 1,144]

I had a similar issue in the past and replaced the collet, but the Bowden still came out of the feeder. Then I cut 3mm of the Bowden tube to give the collet "fresh" material to grab into the tube and now I am fine. 

 

But to replace the Bowden is maybe the better solution because you need to cut it very straight and in the original tube there is a chamfer, but you can give it a try. I used a countersink tool for the chamfer after the cut and it worked for me.

[SandervG 1,521]

If a (defect) collet damages the bowden tube it would indeed be recommended to make sure the teeth of the new collet have a decent part of the bowden tube to grip into. Because cutting a bowden tube does create room for some other issues when done incorrectly, and since a new bowden tube is on its way to @broseph anyway, I would recommend to install the new tube when he gets it. 

[broseph 1]

 

I Installed the new bowden tube, collet. Also put a clip on the collet at the feeder end. 

I cleaned out the feeder (thanks for the instructions sheet!)

Flow sensor has been on, never been disabled

 

Print ran successfully last night. very happy about that! no movement on the bowden tube like I was noticing before.

 

I'm going to run a longer build today and with PVA support to confirm all systems are good.

 

Thanks all for the ideas!

 

 jg