TPU print leave huge gaps in seam
Hi,
Strange gaps are showing up in my seams on inner and outer diameter of a round part. It's as if the layers are not completing.
Details:
Printer: A1 mini
Filament: Creality blue TPU
Speeds/temps: 25mm/s - 230 deg nozzle - 40 deg bed
Nozzle type: 0.8mm Bambu Lab original
Layer height: 0.24mm
The problem is the seam on the inner diameter. It looks like it doesn't finish each layer leaving a huge gap. Have a look in the orange squares in my pic. I've printed this hundreds of times using same filament and nicely dried too, so no strings or other weird things. I've printed it fuzzy skinned because it looks nice.
Any ideas?
RE:
Be realistic, printing TPU with a 0.8mm nozzle won’t get you nice looking prints like PLA and a 0.4mm nozzle, not by a long stretch.
Anyway, to improve things a bit :
1- Check that ‘retract on layer change” is disabled in the settings.
2- Check that “wipe on retract” (or whatever is called in English) is enabled.
3- Set ‘Z-hop’ to 0.
4- Set retraction length to 1mm. or less.
5- Try lower nozzle temperatures.
6- Print slowly (max. 20mm/s).
7- Set ‘seam location’ to random.
8- Check that the speeds of retraction and detraction are aproximately the same.
It occurs to me that 0.24 layer height is very small for a 0.8mm. nozzle. I don't think that this is direcly related to the problem, but you could try a more usual value of 0.4mm layer height, to see if it changes anything.
If you upload here a ‘zipped’ file of your *.3mf project, it would help us to assess the issue.
RE: TPU print leave huge gaps in seam
You're right, 0.8mm aint gonna give me super high levels of detail, but thankfully that's not what I'm after. The 0.8mm with fuzzy skin is more than good enough for this specific part. The reason I use the 0.8mm nozzle is because it's much faster. The same part on a 0.4mm nozzle takes way too long. I tried it on the 0.8mm nozzle and it came out looking pretty good and cut the printing time down by a substantial amount so I stuck with it. I've printed several hundred of these with no issue.
To remove any question about the nozzle I put in a new 0.8mm this evening, but no change. I even downgraded to a previous firmware version because I have never had this issue. I have never had to set z-hop or wipe while retracting or retraction/deretraction speeds etc, it just worked but somehow now there's an issue.
Thank you for your suggestions, I followed them to the letter. I then printed, but it made no change. So, I still have the issue. I have sent you the 3MF file privately in a DM. Please check.
Thanks
Earbud
RE: TPU print leave huge gaps in seam
Dry the TPU thoroughly (I do 55 Celsius over night) , and ideally print from a dry box. I found this to make the biggest difference with TPU surface problems such as zits and wide seams.
RE: TPU print leave huge gaps in seam
Hi....thank you for the reply mate.
So, I did exactly that before I posted and it just doesn't produce the result I need. Super frustrating 🤣