Issues with PETG CF and PLA CF

[Disco_Frank]

Heya al, having issues again with both PLA and PETG CF fillaments
issues here are all PETG CF prints
it has been dried multiple times 8 to 12 hrs or so in a creality drier on the PETG CF setting

I am still new to the 3d printing world, i have done some research and tried some different settings.

• P1s with bambu hardened 0.4 nozzle and gears
• Slicer settings used see pics
• PETG CF i have tried with a different colour but same issues ( no pics sorry )
  this is a mudguard for a Zerode mountain bike,
• I cant get the print to work with PETG CF , see pics as i dont know how to describe , i have done the print in PLA white, with no issues ( pics provided ) so i dont think its the model
  it has been auto orientated by bambu slicer i 1st used the stock settings for a 0.4 nozzle and the filament , after having some issues with PLA matte ( white only i increased the temp on the nozzle ( im in Perth AUS ) ist cold and it def did help a bit, so 3rd print i went up to 270deg and still failed

attached pics A is the original with the only change i was trying to use white pla as a inteface on the support to help with removal, i have stopped this to reduce varibles
B is the best print so far with an increase in nozzle temp ( maybe 260 deg? i did forget to note this ) i did change the walls to aranche too
C is the final one with the settings included but still failed
the white version is in PLA which prints fine to show file is ok ? ok looking at teh print in white… im not sure the file is ok

could it be that its simply the 0.4 nozzle too small for the CF filaments

?

any help is great cheers!

[krellboy]

2 observations.

I’ve only printed BL PETG CF with a .4 nozzle, dozens of kilos, no clogs.

Switching between PLA and PETG in the same print is easy to mess up, the PLA will contaminate the PETG and it won’t hold together anymore. You need to max out the purge volumes.

[Disco_Frank]

yeah, thats why i stopped doing it, help find issues by removing variables was only on 1 print… the other 2 i only used PETG CF or PLA not a mix

[simon14]

Be a bit conservative and slow down print speed, especially over hang areas and support structure. It may help.

[Disco_Frank]

how do i do that? i only know how to do the 50% ,100% 124 etc it seems to my new eye that thats not the failure points?

[simon14]

2 ways:

1. Change maxium volumetric speed in filament profile you are using. Go down to 3 or 9 or whatever lower than the current number. The print speed will be calculated back by the software automatically by using this fomular: Volume speed = xy velocity * nozzle diameter * layer height

2. Force manual print speeds in printer profile

Whichever numer (case 1 or case 2) is lower will overwrite other.

[Disco_Frank]

ok thats great info! ill give it a try overnight!

[sparkyhall]

If you look at the last picture you can see that your poop shoot is full of poop, you need to clear this before doing more prints.

[Disco_Frank]

which is the 1st print that failed… and was remedied ,

[Dextera]

That orientation is pretty … interessting. Is there a reason beside “auto orientation”? From what I see I would put that thing on its feed to reduce that massive overhang …

[simon14]

@Dextera

That orientation is pretty … interessting

It is a mudguard for bike where it will endure shock and vibration. That print orientation is the best for performance as it is strongest along the layer line.

[Disco_Frank]

i wanted to see if that would help, thats all i was trying and testing different things before posting, as a way to learn

[Disco_Frank]

your idea of slowing down the print via the 1st method seems to have worked , ill do that in the future, appreciated the help

[Preet_Grewal]

i have been printing with petg-cf,abs-cf,pla-cf,pa-cf have never had issues. however i make sure to manually purge the last filament about 20-30mm before material change. hope it helps.