I have two Bambu filaments loaded in my H2D. PAHT-CF on left nozzle (external spool) and PETG-HF on the right. The filament speed profiles are the Bambu default. When I print my project with PETG, it prints at a nice reasonable speed and it comes out great. But when I switch to PAHT-CF, it appears to be printing in a ridiculously high speed by comparison, and eventually flings and destroys the part. I’m not changing any speed settings.
I don’t, there’s only one object. The only thing I changed is the filament type between prints. Again PAHT prints in psycho speed, PETG prints slower especially around the wall loops.
But in your case, it’s simply because PAHT-CF in bambu profile has a much lower Minimum Layer Printing Time (5 seconds) compared to PETG-HF (20 seconds).
So it would not slowdown when printing a small part.
It’s not a ridiculous speed, for PA you hardly need that much of cooling anyway. I don’t think it’s wrong.
I have printed many kilos of PAHT-CF since I started using Bambu Lab printers, and I haven’t experienced any issues with the printing speed. The only difference I notice between my two printers is that the H2D produces slightly better quality than the X1 Carbon.
Do you observe any decrease in quality due to the speed?
I have a few go-to filaments for printing:
• PAHT-CF
• PET-CF
• PC
• PC-FR
• PPA-CF
• ASA
Out of these, TPU is the only one I’ve fine-tuned extensively for optimal results. The others provide acceptable quality with the default print profiles.
Okay I found the speed settings that Bjorn was referring to, images below. Looks like PAHT is printing about double the speed of PETG, but still less than 100mm.
Why does the slicer speed settings change so much for the two filaments?
Why would you want it to be printed slow? It’s nylon mate it’s supposedly to be printed hot. Petg and PLA have that minimum layer time very high because they have to be cooled a lot. For nylon if you cool it too much bad things happen…
The reason is because the speed is absolutely trashing the part (see below). I need to read up on the minimum layer time. These are with default speed settings for both filaments.
This is Bambu filament. Not 3rd party. But I will say that I’m feeding it through my own drybox, not an AMS. But in Device tab, i’m actually selecting Bambu’s profile for this filament.
Just by looking at the image, I believe I can see signs of wet filament. Did you properly dry your PAHT-CF before printing?
The reason I suspect moisture is because I see bubbles and signs of cooked filament, as well as a foamy consistency in the extruded material. If my assumption is correct, lowering the speed won’t solve the problem — properly drying the filament will.
Okay yes, i’ll put it in the HT tonight and dry it for another attempt tomorrow. I just was assuming in was speed since it clearly is running much much faster than the PETG (see videos above)
