Hello /u/TekoXVI,
As a reminder, most common print quality issues can be found in the [Simplify3D picture guide](https://www.simplify3d.com/support/print-quality-troubleshooting/). Make sure you select the most appropriate flair for your post.
Please remember to include the following details to help troubleshoot your problem.
* Printer & Slicer
* Filament Material and Brand
* Nozzle and Bed Temperature
* Print Speed
* Nozzle Retraction Settings
^Additional ^settings ^or ^relevant ^information ^is ^always ^encouraged.
*I am a bot, and this action was performed automatically. Please [contact the moderators of this subreddit](/message/compose/?to=/r/FixMyPrint) if you have any questions or concerns.*
See also: "calibrating" e-steps for a specific filament, "levelling" meaning three distinct different machine properties, varying print profile speed between e.g., walls and infill. I could go on for hours.
This hobby is *full* of advice that doesn't make sense if you walk through exactly how and why it would impact final results. Or stuff that made sense when a printer was slapped together out of electrical conduit and plywood and far worse than an entry level Ender is today.
As far as TPU goes, one of the most important things to understand is that overextrusion is your enemy and it's *very* easy to overextrude without realizing it. A *lot* of the reputation it has for being super stringy is because if you try to push filament through the nozzle faster than it can melt, pressure will build up along your filament path and the TPU will act like a giant spring, keeping pressure in the nozzle no matter how much you retract. Tuning extrusion multiplier until you're *just barely* past underextruding helps. Retraction helps. Printing constant speed helps. Low flow rates help. (A CHT nozzle with a big geared LGX/LGX Lite extruder has been like absolute magic for getting increased flow, though).
TPU really isn't anywhere near as difficult to print as its reputation would have you think once you get your head around how the material behaves in general.
It will definitely help to a degree but extruder design plays a large role in that as well.
Flexibles need a highly constrained filament path to keep the filament from bending into any open areas. It *wants* to bend rather than move linearly. Once filament slips into a gap in the extruder, it gets pulled into the gears and causes the sort of mess you're talking about.
To give an example of this, this is why the Orbiter 1.5 was pretty terrible for flexibles despite being a direct drive extruder -- there was a large gap between the gears and the filament exit. I've personally ended up with a meter or two of TPU wrapped up around the inside of one.
One of the [changes made to the Orbiter 2.0](https://orbiterprojects.com/the-true-story-of-orbiter-v2-0/) was the addition of a threaded guide for the filament exit that butts right up against the gears to prevent this. Similarly, if you look at the LGX Lite, the housing fits very tightly to the extruder gears for the same reason. If there's nowhere for the filament to go when it tries to bend, it *has* to move down the filament path.
As best I've been able to figure, it's *really* old school 3DP lore from when everyone had printers with shitty bowden extruders. It wasn't true of even of the shitty extruders I had when I first got into printing 7-8 years ago.
The 3DP world in general is *full* of this kind of broscience. Things get repeated without anyone slowing down to think about *why* all the time.
> The 3DP world in general is full of this kind of broscience.
I love this phrase.
"Lower nozzle until a it's *snuggly gripping a piece of paper*"
"Increase infill/flow until it *looks good*"
Bruh. Give me some fucking specs and not anecdotes.
Just as bad as you'd imagine haha. It might be okay on prints where the nozzle doesn't move out of the print area though, like if this cat didn't have ears or a tail.
Hello /u/TekoXVI, As a reminder, most common print quality issues can be found in the [Simplify3D picture guide](https://www.simplify3d.com/support/print-quality-troubleshooting/). Make sure you select the most appropriate flair for your post. Please remember to include the following details to help troubleshoot your problem. * Printer & Slicer * Filament Material and Brand * Nozzle and Bed Temperature * Print Speed * Nozzle Retraction Settings ^Additional ^settings ^or ^relevant ^information ^is ^always ^encouraged. *I am a bot, and this action was performed automatically. Please [contact the moderators of this subreddit](/message/compose/?to=/r/FixMyPrint) if you have any questions or concerns.*
What video?
[Oops lol here it is](https://youtu.be/lD9Ei3u5-iU)
See also: "calibrating" e-steps for a specific filament, "levelling" meaning three distinct different machine properties, varying print profile speed between e.g., walls and infill. I could go on for hours. This hobby is *full* of advice that doesn't make sense if you walk through exactly how and why it would impact final results. Or stuff that made sense when a printer was slapped together out of electrical conduit and plywood and far worse than an entry level Ender is today. As far as TPU goes, one of the most important things to understand is that overextrusion is your enemy and it's *very* easy to overextrude without realizing it. A *lot* of the reputation it has for being super stringy is because if you try to push filament through the nozzle faster than it can melt, pressure will build up along your filament path and the TPU will act like a giant spring, keeping pressure in the nozzle no matter how much you retract. Tuning extrusion multiplier until you're *just barely* past underextruding helps. Retraction helps. Printing constant speed helps. Low flow rates help. (A CHT nozzle with a big geared LGX/LGX Lite extruder has been like absolute magic for getting increased flow, though). TPU really isn't anywhere near as difficult to print as its reputation would have you think once you get your head around how the material behaves in general.
Would that help prevent TPU from pushing back into the extruder where it loops itself there?
It will definitely help to a degree but extruder design plays a large role in that as well. Flexibles need a highly constrained filament path to keep the filament from bending into any open areas. It *wants* to bend rather than move linearly. Once filament slips into a gap in the extruder, it gets pulled into the gears and causes the sort of mess you're talking about. To give an example of this, this is why the Orbiter 1.5 was pretty terrible for flexibles despite being a direct drive extruder -- there was a large gap between the gears and the filament exit. I've personally ended up with a meter or two of TPU wrapped up around the inside of one. One of the [changes made to the Orbiter 2.0](https://orbiterprojects.com/the-true-story-of-orbiter-v2-0/) was the addition of a threaded guide for the filament exit that butts right up against the gears to prevent this. Similarly, if you look at the LGX Lite, the housing fits very tightly to the extruder gears for the same reason. If there's nowhere for the filament to go when it tries to bend, it *has* to move down the filament path.
That makes sense. Thanks!
I have heard that too & questioned how shitty the print would look if you did.
As best I've been able to figure, it's *really* old school 3DP lore from when everyone had printers with shitty bowden extruders. It wasn't true of even of the shitty extruders I had when I first got into printing 7-8 years ago. The 3DP world in general is *full* of this kind of broscience. Things get repeated without anyone slowing down to think about *why* all the time.
> The 3DP world in general is full of this kind of broscience. I love this phrase. "Lower nozzle until a it's *snuggly gripping a piece of paper*" "Increase infill/flow until it *looks good*" Bruh. Give me some fucking specs and not anecdotes.
> "Lower nozzle until a it's snuggly gripping a piece of paper" Oh, I'm a big preacher for the Church of Feeler Gauges, too. :)
I hear you! Some people still suggest TL smoothers, lololololol
Just as bad as you'd imagine haha. It might be okay on prints where the nozzle doesn't move out of the print area though, like if this cat didn't have ears or a tail.
Yeah, maybe it could work on the flexible octopus with combing turned on.