Bought some gray Bambu TPU HF to print myself a phone case since Apple’s own are terrible and keep falling apart on me after a month or 2 this generation - both silicone and that ‘finewoven’ stuff.
Anyway just came here to say Bambu’s TPU HF appears to be complete junk. It’s much softer than other 95A hardness TPUs I’ve tried and it oozes like mad no matter what temp settings I use. Using an X1C with a fairly new 0.4mm hardened steel nozzle.
I’ve tried drying it for over 30 hours at 70C (in a MCU controlled dehydrator which is monitored by an additional inkbird BLE thermometer so I can make sure it hits the right temperatures as the last dehydrator destroyed a few rolls by being a lot hotter than it claimed),
$ gatttool -b 2C:AB:33:[redacted] --char-read --handle=0x2d | awk '{print"printf \"%d\n\" 0x"$4$3}' | sh | awk '{print"echo \"scale=2\n"$1"/100\""}' | sh | bc
69.97
printing immediately after drying, lowered the printing temperature from 230C down to 185C in 5C steps to prevent oozing, and it still can’t do a single non-printing move without spilling liquid TPU across the print and eventually failing.
Yes you read that right, it’s oozing even at 185C, 45C less that its default temp in Bambu’s profile and 15C less than it’s claimed minimum printing temp - still oozing to the point of being unusable. After 30+ hours dehydrating at 70C I’m fairly confident it’s not a moisture issue at this stage. The formulation for this stuff just doesn’t match the printing profile at all.
I’ve also tried raising and lowering the max volumetric and move speeds.
What’s the story with this stuff? Why is it so trash? It’s literally the worst TPU I’ve ever printed with.
Have you calibrated the Pressure Advance? Is it oozing or is your Pressure Advance way off? I find it is often off by a factor of 10 for TPU. I typically end up between 0.3 and 0.5 for BL TPU and not the .02 default. I have printed black and white with no issue.
It’s an X1C with LIDAR that tests the pressure advance before every print, so I wouldn’t expect it to be off. I’ve printed other brand TPU using the generic profile without issue.
Also I don’t think pressure advance would be related to this stuff oozing during non-printing moves at a temp as low as 185C. That can only be the formulation.
Just for fun though I’m going to try upping the max volumetric to 15mm3, temp to 240C so it’s nice and liquid, and run the thing in ‘sport’ or ‘ludicrous’ modes. Maybe I can make it move fast enough that there’s no time to ooze
I’ve had similar experience, bag was punctured on on a arrival. I printed with it anyway to check for fitting. It was horrible, blobs and strings. After drying it for 3 hours it seemed much better, left it for another 12 hours and printed nicely. I turned off the dryer and within 3 hours it was horrible again it was a very humid day though but I didn’t expect it to get so quickly. I also thought it was softer than the normal 95A, I had to thicken up my phone case for it to work properly.
Luckily the Bambu stuff isn’t silly priced like the Polymaker HF TPU ($50), so it could be worse. However, I’m finding quite a few 1kg HF TPUs at $25-35 (I have some $30 Overture HF and its very similar to Bambu 95A HF). Honestly, with TPU, I’m not looking for the world (as far as features). If its flexible and prints well, its good to go. There just isn’t a lot to pay extra money for, so its hard to ignore the price difference.
Bambu’s could be a hair better at this and that, but in all honesty, I can’t think of anything I would say is worth an extra 30% on Overture’s $30 price tag. I’m sure there’s lots of diminishing gains for each dollar spent over that initial $30.
So long story short, Bambu’s TPU isn’t crazy priced like Polymaker’s, but its not well priced either. Being it can’t be used in an AMS unit, there really is no good reason to spend the extra money on it. Personally, I’m using the Bambu HF profile on the Overture HF filament and they pretty much print the same. I can still see myself buying more of the Bambu TPU but, I can also see myself shopping around before doing that.
That sucks, I can’t say that is what I’m seeing. Its pretty much plug and play for me. The BBL HF TPU profile works fine for me.
The only suggestions I’d have is check for issues in the extrusion path. Maybe the line has some binding up that the extruder has to overcome at times and that is leading to odd extrusion. Double check there isn’t an odd K-factor on the printer’s profile of the filament. Maybe even test a small print on the old profile for non-HF TPU and see if it still oozes.
Yeah I haven’t been paying much attention to other brands of late, since I’ve been getting all my filament for free now which is always the best price for me
Also we tend to have to pay a premium in Aus for most imported stuff, so my selection is not as big as you guys in the US. I probably only buy one roll of TPU a year. I’ve uploaded TPU things to MW and have received a spread of too big, too small complaints so TPU doesn’t appear to be as consistent as the usual stuff.
I buy way more filament than I need. I still have the 1st roll of TPU I ever bought from years back, also have 2 rolls of BBL HF, and 1 roll of Overture. No good reason for me to have that many, because like you, I might use a roll a year, but I like to have one black and one white roll, so I got the two BBL HFs. The Overture was something I got before the BBL HF was available, and honestly forgot about while waiting to finish the other old roll.
Interesting on the complaints, are you uploading print profiles as well?
I did but it was a generic tpu one, as I didn’t have any bambu stuff back then. I even had someone upload a profile for the A1 mini, because he/she said it was ok in one axis but not the other. Go figure
It’s way too expensive, considering you don’t ever get anything usable from it. After drying it for 30 hours at 55deg (my dryer’s max temp), I’m unable to print anything. I really don’t see the point of printing tpu fast in 3 days time. The amount of energy wasted trying to dry this stuff for one or 2 prints seems like a gimmick to me. You could just use generic TPU dry it for 2 hours and start printing like I’ve done for years. Maybe if all you do is print TPU then it may be worthwhile investing in a furnace to print from and store it in since it’s wet again 10 minutes after the dryer is turned off. Definately will never buy this stuff again. I’m thinking of chopping it into small pieces to use as desiccant
Update: Turns out the default profile wasn’t the best. What can I say, I’ve been spoilt for the last 12 months. The retraction length is overridden to 0.8mm in the filament profile, which is the same as the machines default retract. Setting it to 2.5-3.0mm seems to fix the stringing and oozing for me.
