The past couple weeks or so, I’m getting overextrusion/blobs wherever I have somewhat sharp edges (and elsewhere)
There also appears to be a correlation between the locations of the blobs and where my retraction/unretracted areas are showing in OrcaSlicer whenever I print ANY PETG
I am an intermediate level 3D printer with a few years experience and I am just absolutely stumped because I have been printing these exact files for over a year now with no issues whatsoever. I have tried the basics following:
- Dry Filament
- Re calibrate Flow Dynamics, Flow Rate, PA
- Retraction test (which come out perfect everytime)
- Increase retraction length to 1.5mm
Nothing seems to work whatsoever, and I end up with all these artifacts as shown earlier
I have 7 of these printers and they ALL seem to do the same thing, seemingly out of nowhere to any PETG prints i try.
I wonder if Bambu did something on a recent firmware update or something? Either way, it’s quite frustrating as I run a business with these things and have spend an exorbitant amount of time already trying to diagnose this, instead of working on the business
I would really appreciate any of you experts take on this and what I could potentially be doing wrong. Thanks in advance
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I myself did not have good results with z-hop while retracting. In my experience, it just gives additional time and travel for oozing.
Inversely, enabling wipe while retracting solved a lot of issues for me as it essentially gives a useful use to the ooze.
There’s also a chance that a 25% increase in retraction speed helps a little bit.
I noticed some odd things with undocumented changes since I started with Bambu.
Making it hard to keep files for models to just print if suddenly the prints come out in bad quality.
For oozing filaments like PETG it can often help to reduce the print temp by just a few degrees while also changing the retraction speed.
It’s a bit of a hit and miss with the retraction distance and speed and one has to test things out first.
The goal is that together with a good k-factor the nozzle won’t have any leftovers coming out at the end of a line.
In some cases those blobs can be a result of build up around the nozzle.
If that’s the case you should see it happen while printing.
Tried these settings and the results are even worse. I am absolutely stumped at this point.
If you suspect an update caused the change in behavior, have you tried rolling back the firmware version from the Handy app and/or using an older version of the slicer?
I have forsure thought of it — but more so of a last resort if I cant dial it in properly or noone here has any ideas. May have to go back to the 1.9.X versions of Orca where I didn’t have these issues.
I just wish Bambu would provide a meaningful place for users to share their experience with updates and changes.
Their change logs are incomplete and we drown in topics dealing with issues we never had before…
That’s just not right and simply shows that the development does not work as advertised.
It’s extremely frustrating to say the least. Especially when so many people are running these for business purposes.
Well, if the z-hop gives unsatisfactory results, then retract at layer change will just give more of the same.
The default retract speed should be 30mm/s. You can up that to 40mm/s with PETG if you enable the relevant check-box. I have found retract speed to be much more effective than retract distance above 1.2mm. And you may want to loose z-hop altogether but keep the wipe. Having the nozzle leave the print is just inviting oozing.
Finally, how sure are you that all rolls you have dryed are truly dry? Since the issue developed over time, something must have changed. Or could you have some nozzle wear from, for example, particle loaded filaments?
I know from all my old printers that certain filaments are a pain.
With the right print temp they love to ooze out of the nozzle because they keep getting runny quickly.
To avoid spiderwebs and such we play with the temp, the retraction and what not…
In reality though we should expect these days that complicated filament get matching setting and profiles that actually work…
After all, that is part of why we decided to pay so much and why we went with Bambu…
In hindsight I guess most users now wish they would have paid a different company the money for a new machine…
