Is TPU the best material for this?  

RE: Is TPU the best material for this?

@trevor-wilkins

I'm in the states and we are having some pretty serious supply chain issues, it seems to be driving the prices of everything up as well.

My advice would be to buy some less expensive filament, I was searching on Amazon UK to see what was available there that I knew to be good quality and inexpensive, but it was slim pickin's unless they were blocking results to the US. I did notice a couple of rolls of YOYI brand TPU available I have printed with it, they falsely list it as 85A, It's not. I have tested it with my A durometer and it tests as a 99A it print like it also.

I wasn't unhappy with the filament other then I bought it thinking it was an 85A. It prints easy as TPU's go and it's cheap enough for you to play and experiment with for this task. I do not think Sainsmart brand will be a good option for this.

Good Luck and thanks for letting us know how your project went.

Swiss_Cheese

RE: Is TPU the best material for this?

@swiss_cheese

Thanks. That's really useful advice. I didn't see any on Amazon so I'll check it out. I'm sure it will be useful for other things too.

RE: Is TPU the best material for this?

@swiss_cheese

I got some of the TPU that you suggested but now my extruder is clicking as it doesn't like it. Any suggestions as to best settings? The packaging just suggests 200-220C

RE: Is TPU the best material for this?

Usually clicking means you're trying to print too fast.  you should stop as soon as you start hearing that as it can end up wrapping around the gear.

RE: Is TPU the best material for this?

which one did you end up getting?   you might want to zip up and post your .3mf here so we can see what speeds/temps you're trying.  Swiss and I both just went through a couple days of troubleshooting some ninja flex that appeared to come from the factory too wet and needed drying.  We were up to 248C printing temp.  In our case it would stop extruding at the normal temp he had been printing with at 230C.

You're trying to push a wet noodle through the eye of a needle lol.  you need to make sure there's no back-pressure whatsoever or the filament will just bend in the extruder and not make it down to the nozzle.

you probably shouldn't print faster than say 15mm/s to start.  you'll also want to make loose up the idle tension bolt a little from normal.  if you bump your temp up a bit it allows the filament to flow more easily through the nozzle and thus prevents back-pressure.

What filament profile are you using as your starting point?  With the ninjaflex the one you'd start with is "SemiFlex or Flexfill 98A" and adjust the nozzle/bed temperature accordingly for the specific filament.

RE: Is TPU the best material for this?

@trevor-wilkins

it's also very important adjust the idler tension for TPU/TPE

I'll explain to you how I do it,

So what I do is preheat the hot end for FLEX then I loosen the idler, to the point that it won't quite pull/push the filament in and I manually feed some through the hot end, then with Alan-wrench in hand, I select the load filament from the menu. The extruder will turn but not feed because it's to loose. use the Alan-wrench to very slowly turn the idler screw until it just barely grabs and starts to feed filament out of the end, then stop and print a test square 100X100 or whatever to see how it flowing and don't make adjustments of more then an 1/8 turn at a time If any farther adjustment is needed.

Notes:

It's important to use the flex preheat for this because the loading feed rate is set for it.

I have some other tricks that I use for loading as well, "but not yet"

The 100 X 100 is the best test for this to be sure your getting what you need from the extruder

I use these settings for almost every filament once I have it where I want it, now a days it takes me about 5 min to set.

only times I change these adjustments is if I using something really hard with Carbon F or Fiber Glass in it.

Hope this helps, I'm paying attention to the thread in case you need more help, TPU can be tricky sometimes.

everything Ssill2 said is valid also

Good Luck

Swiss_Cheese

RE: Is TPU the best material for this?

What swiss said 🙂

RE: Is TPU the best material for this?

@trevor-wilkins

I'll offer to take a look at your project if you want to post the zipped up .3mf file I can make adjustments if needed and re-post for you to use as reference or just print from, but its important to get the idler tension correct first <-- just reiterating  

How-to-save-and-upload-a-project File if your not familiar already.

Swiss_Cheese

RE: Is TPU the best material for this?

forgot to mention: also very impotent if your printing TPU/TPE on smooth PEI sheet use a separator e.g, Glue stick, magic goo etc,, whatever one your used to. the TPU's will bond very strong to the smooth sheet. with the textured sheets either regular textured or Satin your fine just to print directly on the sheet.

I assume based on your original post that you had some prior TPU experience, if not your about to have a fun time (By fun time I mean trying time)

Regards

Swiss_Cheese

RE: Is TPU the best material for this?

@swiss_cheese

Thanks for the great advice. I had already tried and failed to get anything decent printed and now I can see why. The TPU is much softer than PLA isn't it?

Extruder and bed are now cleared so I'll have another try next week.

I've attached the file which is my first and only attempt with the TPU (done before I saw your answers). I need to dig into PrusaSlicer some more to see the options you mention. Quite new to this but very happy with the machine as it's printing everything else very well.

Thanks again.