Bowden tube pop's out

So ive been printing some larger projects with my cr10s pro. And intermittently it seems the bowden gets ripped out from the extruder side causing filament to go all spagettie around the printer.

So settings wise this printer has mostly been printing pla and has completed a 60 hour print with the same spool of pla. Ive used the same slicer stock settings for the cr10s pro in prusaslicer and used the stock settings for prusament pla.

Currently my fix has been replace the bowden tube as it has cut marks in it from the push in fitting.

The push in fittings seem in good order, and ive never had this problem with my other printers. Of which i usually go with stock prusament settings.

Other than go direct drive, what ideas does the hive mind have for this.

If i had to guess it seems to be creating too much pressure behind the nozzle, and that coupling may be the weak spot. Could it be worth while looking into a different style of coupling or different hotend (its currently the stock creality one which has silly nozzle threads). I cant confirm the other times if ground up filament was an issue too, but judging from the scrap filament from this mess, it looks like there was a good bite out of it from the extruder.

I cant confirm if this issue has occured with capricorn tubeing, as currently ive installed some stuff i got in bulk from 3dpc.

Any ideas/suggestions are all appriciated.

The push-in fitting’s one job is to hold the Bowden tube in place. The fact that it’s failing at it screams that it’s internal pins are broken/bent. Replace it.

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Doc, check the diameter of the replacement tubing. It is not always the same if it is smaller it may not grip tightly in the fittings. replacing them is an easy so you might as well. Check the diameter it does vary.

How large are your retractions? How fast? A long print with lots of long fast retractions may put extra strain on everything, especially with Cap tubing it is a better fit than most, but that transfers more stress to the fittings.

It might be worth slowing retractions some.

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Any possibility of a partial blockage creating increased pressure?

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One thing I see on some printers that have had this problem the solution was a clip to under the press in part of the fitting … to keep it from pressing in during retractions.

Ill try that and see how it holds up.

Ill have to check the stock settings for my retractions. Ive already changed the tube but am useing the knockoff stuff i bought from 3dpc. I do have just enough capricorn tubing for 1 more replacement.

Its always a possibility. I did have a clog previously, like more than 100 hours of printing previously. Since then ive been running off a single 5kg roll of pla. Though my shop has been a bit dusty latley. Ill double check the nozzle is cleared with a cold pull.

Ive seen these too, but never really understood how they helped as my original printer never had this issue and never had these clips.

Ill print some up as it cant hurt.

Thanks for the idea. :slight_smile:

I use the ones from 3DPC that have the black tops.
They last longer than the original or capricorn ones, and I’ve never used clips on them.

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So ill make an update in the future how things work out.

I changed the push fitting. It was an “issue” upon further inspection.

I suspect my original issue may have been my bowden tube may have not been seated far enough into my hotend. So i fixed that.

After all of this in an unrelated note. I had to replace the part cooler shroud. Though i have spares printed beacuse the stock design is kinda poor. So now trying out a new design i found on thingiverse.

As of this post, about 14 hours of successful prints.

You use what exatly from 3dpc? Bowden tubeing, push fittings or the little clips?

Sorry, realize I wasn’t clear with my post.
I use the push fittings with the black tops and I don’t use the clips.
I have the Ender 6, original push fittings failed quickly, changed to the Capricorn fittings.
They failed, I switched to the fittings with the black top and they are still going strong 3 months later.

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In conclusion to my problem. I suspect my hotend was clogging due to user error on hotend assembly. Seems to be working now though. :slight_smile:

Thanks for the ideas.

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