Hi all.
Hopefully someone can spread some light on an issue I have.
I’ve recently printed batch of clips using white bambu pet-g and every one is brittle and has no flex and even snaps.
I’ve been making these clips with eSun pet-g for the last two years and I dry all my filament for 8hrs at 65d but thinking maybe I missed this reel I dried the filament again over night and the problem is still there. I’ve now also tried my other reels of white bambu pet-g with exactly the same results, all brittle!
The print file is one I’ve been using for a long time so I know it os good. I also used a black eSun pet-g and the print is perfect, not brittle at all.
I’ve checked both the black eSun and the white bambu on my other bambu lab x1 and i’m getting the same results, so its got to be the filament right?
One of the machines had a new nozzle yesterday so it’s very unlikely it could be that? Especially as the black eSun is good.
Print settings used are the standard .20mm Strength with the first layer height changed to .28mm and the seam set to rear. No changes made on the filament settings.
Has anyone else had this issue? is Bambu Pet-g known to be brittle?
Update.
I have just printed the same STL using the white Bambu Pet-g on my ender 3 v2 with my eSun settings, lower print temp and slower speed, and although the settings are not tweaked for this filament the clip is not brittle at all and functions as it should.
Could Bambu’s settings be incorrect? Under extrusion? printing too quick?
Following.
I also use eSun PETG for most of my projects but I have 4-5 packs of Bambu PETG on the shelve to try.
What speeds/temp do you print your projects on?
With eSun PETG I’m printing at 250C but I’m slowed down the walls to 80 mm/s to give it a nice glossy look and for better layer adhesion. I found the stock PETG profile left the object matt with poorer layer adhesion. I am using ORCA and did a full calibration for eSun PETG.
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Problem Solved!
Thanks for all the input everyone 
Anyway, just incase someone else has the same problem. I’ve increased the infill/wall overlap from Bambu’s setting of 15% to 20% and it seems to have resolved this issue.
I’m still not sure why this is only an issue on all my white bambu pet-g filament but it’s solved.
Stick in and off you go.
I’ve found the print quality on the standard settings from bambu to be really for what I need, apart from the issue above obviously.
My (probably still unfinished) journey with the BBL PETG has been a long one. Perhaps I just got a bad batch, but the default settings have been so far off it’s absurd. I had identical poor results on both my X1C and P1S using the defaults. After calibrating using the Orca calibration tools, and a lot of trial & error, I got something that looked quite good, though. Even better than eSun PETG, which has been my most consistent PETG so far (Polymaker and Overture are not too far behind).
I changed a lot of defaults, and here is a partial list:
- flow rate 1.0324
- pressure advance 0.042 (a record for the highest ever for me)
- 0.6 spiral Z-hop
- Z hop on layer change
- 2 mm retraction distance, 25 mm/s for retract, 12 mm/s for deretract
- added 0.02mm of Z offset in the filament gcode start settings
On the process settings, I dialed the outer wall speed down to 90, with 110 for the inner walls.
The under-extrusion problem was easy to solve, but then there was a lot of buildup of material on the nozzle that affected surface quality. That’s where my journey with the settings got long and interesting, but the result was great. Here’s a zoomed-in shot that shows all the details:
The 45º overhang at approx 1 o’clock was particularly hard to get right.
BTW, I found that using the wipe settings to try and clean up the nozzle ooze just made things worse.
I make a lot of functional parts, and print in PETG a lot, so I need consistently good results. The extra effort was worth it, as it improved my custom settings for my other PETG filaments as well. With experience, I have found that slower speeds are really only necessary with small parts or ones with a lot of small details. For larger, low-to-medium detailed parts the normal speeds work fine using 10-12 mm3/s depending on the filament, which results in a max speed of 111 - 133 with 0.2 mm layer height.
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Thank you so much for sharing all this info! Looks like your hard work has paid off 
I though my issue with the delamination between walls had been resolved but it hasn’t and now back to square one. I’m currently trying to print with lower inner wall speeds to see if that resolves the issue.
I’m going to try your settings next. I’ll let you know how it goes.
