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kmanstudios

The Clumsy Noob has Chew Marks and the Problems It can Cause

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OK, as I was testing out a file for a fellow board member, I switched filaments. All things seemed ok. Then at 3AM I got a phone call from a private number (grrrrrrrr). But, I used the opportunity to check the print at the 3 hour mark.

And, I was printing air with the printhead swinging above the partial print like it was trying to will the rest of the print into being.

No, I said to myself....this cannot be! My last print with that filament woiked. Coitanly it should be woiking now. Nyuck, Nyuck, Nyuck.....

Well, I killed the print. Damned be to my expectations as the proof of failure was laying on the buildplate.

So, I found the issue. I bring this up because I have seen a lot about failing prints and such and most advice points to a nozzle issue. Now, that is solid advice. But I discovered something that I was not fully aware of and wanted to share this.

The picture below was the culprint (see what I did there? :p).

The filament had been slipping and getting chewed a bit and that was all it took to clog up the bowden tube. The picture below shows that when grinding a bit at times, the filament gets a bit ground up and creates areas that are demonstrably larger than the diameter of the filament. This, of course, means friction and more slipping and more chewing and more....well, you get the idea.

So, I pulled the full length of the tube out the front until I had smooth filament. And, I will be using the 'wasted' filament as part of my nozzle cleaning process as it has a lot of good areas.

Hope this gives another noob something to chew on......oh, I am so punchy this morning LOL It also points to making sure your filament is within tolerances as some are a bit dodgy on maintaining that firm diameter within tolerances.

As a quick aside, this also creates issues when entering the nozzle. So, it can affect the nozzle too and that is why you should check both as I did have to pull a piece of plastic that broke off due to pressure on the weakened, chewed area. So, I really had a double clog.

ChewMarks.jpg

Edited by Guest
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There are a few reasons the filament can get get chewed up like that. It's kind of a chicken and the egg issue.

Ultimate cause: Something prevented your filament from moving, so the feeder chewed on the same part of the filament for a period of time, instead of advancing it.

What caused the filament not to move? That's where it gets trickier to diagnose. Either the filament was caught on something on the spool side so it couldn't advance that way, or there was some sort of impairment either in the bowden tube or the nozzle. Debris in the bowden tube can cause flow issues. Also, burnt material in the Core cause issues, as well as problems if there's residual material in place and you switch from a higher temperature material to a lower temperature one.

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I also noticed that different makes of the same material (say 3 different manufacturers of PLA) can have different properties such as firmness or surface friction. I notice that I do have to adjust my tension a bit on different types of filament.

And, it just gets exaggerated when going from something like a PLA to a PETG to a PC and I am assuming (Have not tried it yet) PP as well.

Sigh...so many things to take into account. I really do need at least 2-3 more printers to keep up with my design process as I am now encountering 3-8 day prints and different materials.

Would be nice to dedicate a machine or two to a subset of materials and just have more than one print running at a time.

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I also noticed that different makes of the same material (say 3 different manufacturers of PLA) can have different properties such as firmness or surface friction. I notice that I do have to adjust my tension a bit on different types of filament.

And, it just gets exaggerated when going from something like a PLA to a PETG to a PC and I am assuming (Have not tried it yet) PP as well.

Sigh...so many things to take into account. I really do need at least 2-3 more printers to keep up with my design process as I am now encountering 3-8 day prints and different materials.

Would be nice to dedicate a machine or two to a subset of materials and just have more than one print running at a time.

What about dedicating an additional print core to a certain set of materials? Or doing some thorough cleaning in between. Unless the diameter is different, I don't think you would need to change the tension on the feeder, do you?

Sounds like a lot of prints! Anything you can share regarding all the projects you are working on? :)

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What about dedicating an additional print core to a certain set of materials? Or doing some thorough cleaning in between.

Oh yeah....right...throw it back on me!! LOL :p

Usually I am pretty good about cleaning, but sometimes, not so much....like changing out a print and filament at 2 or 3 AM.

Unless the diameter is different, I don't think you would need to change the tension on the feeder, do you?

I would tend to agree, but I noticed that different manufacturers can have materials that are stiffer/softer/slicker/etc. than others. And, it is possible, I missed the change from a generic 3.00MM (really 2.85) and a real 3.00mm diameter.

Sounds like a lot of prints! Anything you can share regarding all the projects you are working on? :)

Just a squirrel trying to get a nut. My schedule exploded a bit in the last two weeks and all I have been able to do is cycle prints in and out. Well, that and designing. I am just trying a lot of different things. For instance, I went nuts on spiralize type of prints (somethings like about 30 of them) that I need to make bases for and then light. I am trying to rearrange the apartment/studio to be more efficient for work. Not an easy feat.

But, I will get some prints up when things are not 'half done'. I also went on a 3D Fractal binge. Sadly, most of my prints are anywhere from 70+ hours to about 190+ hours.

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Hey, I am all in favor of you buying a couple of extra Ultimaker's if you prefer :p

And could be that some materials have like an oil on them, I spoke with a filament manufacturer that did that once. And perhaps this could negatively influence the grip our feeder has on it. Have you ever cleaned your knurled wheel, so there is no plastic dust in between all the teeth?

Looking forward seeing all those projects :)

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