TPU - Gonna Give It A Try! Any Suggestions Tips Tricks ?

Yup, I bought a roll of OVERTURE TPU: https://amzn.to/3qFdQLA

Crazy, right?!?!

I'm gong into this expecting to have a lot of problems and challenges, but figured I'd see if I could get it to print on my stock Ender 3 V2. There are tons of videos where people have successfully done it, so I'm going to watch, learn, and give it a go.

... then WHEN it fails, I might start some of the tweaks to hardware, settings, etc., to see if that makes a difference.

I'm also giving myself permission to quit at any time... especially if I find I'm getting flustered and frustrated. LOL!

While I decide on which prints to use as tests, I figured I'd post here to see if y'all had tips, tricks, suggestions, or just words of encouragement.

Nifty said:

... then WHEN it fails, I might start some of the tweaks to hardware, settings, etc., to see if that makes a difference..

I'm also giving myself permission to quit at any time..

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Ignorance is bliss, because you don’t know anything and you’re not expecting it to work.. So it just might..

I have my roll of flexi here but haven’t tried it yet because with one printer down I don’t want another, I plan on upgrading the whole hot end, heater block radiator and thermistor when I get a chance, and I reckon that should be more accommodating to my flexi roll friend..

If it works then that will be great and if it is troublesome then I’ll just put it down to inexperience and that will be that, I don’t see why I should look for trouble when PLA works so well and I am very happy with it..

It wasn’t the Apple on the tree that cause all the trouble.. It was the pair on the ground…

@Nifty, you may purchase a few tons of ”patience”..

Knowing little about your printer, I can give no real advice about tweaks, tricks and so forth. but don’t start with a very soft TPU ( hardness below 85 - 90A). I see that this Overture you purchased is rated Shore 95A, like the TPU-95 from Esun that I print with my Prusa. Once you know the limitations of flex filaments, it’s no more challenging than PLA or PETg, Instead, I tried once TPE-70A and it was a fiasco. That stuff is softer than boiled noodles.
I guess that with a Bowden extruder even 95A may be difficult, so keep us updated about your flexible adventures.

Artur5 said:

Knowing little about your printer, I can give no real advice about tweaks, tricks and so forth

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Yup, makes sense! Fortunately one of the pros of having the Ender 3 V2 is that it's so popular that I've found a ton of videos online with people showing how they printed TPU / Flexibles on the same printer... many even using "stock" Bowden printers.

Artur5 said:

but don’t start with a very soft TPU ( hardness below 85 - 90A). I see that this Overture you purchased is rated Shore 95A

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Exactly! I specifically went for a "harder" TPU to hopefully increase my first-time learning success.

Well, that was almost too easy!

(granted, the thing I printed was SUPER basic and simple)

My girlfriend LOVES her "fizzy water", so she has a SodaStream to make it daily on-demand.

Today I went to put in a new CO2 cartridge and right when I inserted it, I heard gas leaking everywhere!

I was pretty sure it was a gasket / O-ring issue. I didn't see anything but hard plastic on the device mating with the brass coupling on the canister.

After some Googling, I verified that there should be a rubber gasket between the two... but NO idea where the original one ended up!

Well, this was the motivation I needed to finally open up the new Overture TPU I got a month ago and give it a try.

I quickly took measurements with my calipers and designed a new o-ring in Tinkercad, then printed two mockups in PLA (since it was already in the printer) and was happy with the perfect fit of the 2nd try.

I opened up the new TPU bag and got to printing. I didn't change a ton of settings. Mostly just increased the temp to 220, set the layer height to .2mm and (most important) set ALL printing speeds to 20mm/s!!! (bed is PEI sheet at 50 deg. and lots of gluestick)

Well, during the first print I realized that the infill was set to 60 mm, so I stopped the print, changed the CURA settings to 20, and printed it again. Came out great!!!

Tested it in the machine and it's working 100% perfectly! I'm not sure how durable this TPU is, or how long it will work in this use case, but I'm optimistic it should be fine.

Here's a pic with everything above (final gasket is in the device)!

I was SO nervous about printing in TPU. My biggest concern was the bowden setup isn't ideal for flexible materials... but in a case like this, it seemed to work just fine.

I was also worried about adhesion to the bed. I've heard horror stories about it not sticking enough, or sticking too much. I think the gluestick totally resolved this issue.

I'm sure with a bigger and more complicated part I'd have to deal with a lot of stringing and have to tune a lot more settings, but so far, I'm very pleased!

(oh, and I've seen enough videos online about how much TPU sucks in water from the air, which can totally mess it up in a hurry, so I didn't leave the roll out for long at all, and after the print IMMEDIATELY put it in a vacuum bag with desiccant, sucked out all the air, then put that whole thing into a dry-box that's got more desiccant and is sitting at 18% humidity. That should keep it nice and new!)

Here's the design:


Here it is on the printer:

Good news !
In my limited experience, TPU isn't that tricky if you stay within reasonable limits of hardness and avoid complicated designs, specially with overhangs.
I've printed some small O-rings myself. They're OK, but TPU hasn't the same properties as nitrile rubber and other stuff used for these parts,. If you stretch the TPU ring a lot it won't shrink back to the original dimensions. Every time you do that, the ring gets enlarged a bit. Hence, if you have to stretch it a lot in order to remove it from the place where it's installed, chances are that it won't make a good seal anymore when you reinstall it again.
Of course if the part is quite large it will stand better 'torture tests' than a very small ring.
Anyway, I consider my TPU O-rings as 'single use' parts (a bit like single use chips for inkjet carts. )
Cheers,

Artur5 said:

TPU isn't that tricky if you stay within reasonable limits of hardness and avoid complicated designs, specially with overhangs.

Click to expand...

I was surprised how flexible the filament is that I got and thought it would get gummed-up in the extruder gears, but it seemed surprisingly fine.

Yup, I'm still a bit nervous to print anything with overhangs, lots of retractions, etc. etc. etc.

Artur5 said:

Anyway, I consider my TPU O-rings as 'single use' parts

Click to expand...

Ah, good to know! This is one that is compressed, held in compression for 99% of it's life, so we'll see what happens.

(that said, I went ahead and purchased this $12 kit: https://amzn.to/3yaXT48 )

I just printed this phone case on my Ender 3 pro (standard Bowden setup) in Sunlu TPU. Bridging and overhangs worked out quite well. Took about 7 hours at 15mm/s. Sliced with SuperSlicer, 2.5mm retraction, and using pressure advance and Klipper firmware.