I am preparing for my first print with PC filament (Bambu PC is on its way) and am considering the details. I looked at the default profile for Bambu PC (which I want to use as a starting point) and, to be honest, I am not entirely convinced by the cooling parameters (set as default), especially these values:
Min Threshold: Fan Speed 10% / Layer time 30s
Max threshold: Fan Speed 40% / Layer Time 12s
Fan Speed Overhangs 60%
Keep Fan always ON
Based on what I’ve read about PC printing so far, these values seem pretty high to me… I would expect much less/lower cooling
On the other hand, I have never printed a PC before (so far my experience ends with ASA and PA12), and whoever came up with this profile probably knows what they are doing (and, more importantly, it is a Bambu profile for a Bambu printer and Bambu filament, so it should be “right”). However, I don’t want to rely on it completely and struggle with nonsensical settings during my first prints…
So I want to ask what your opinion is on the above cooling values… Do they seem OK to you? If not, what values do you use?
I have used Polymaker Polymax PC for quite some time and recently bought a spool of Bambu PC out of curiosity.
For the polymaker PC, i set all fans of, like for almost any high temperature filament.
I think I also tested Bambu PC with both standard profile and all fans off.
Still bringing my daughter to bed, but when she finally is asleep, I will have a look at the test results and let you know.
So here are my test results:
The BambuLab deals surprisingly well with a little bit of fan. at 10% fan, layer adhesion drops a bit but by far not as much as I expected.
That being said, the layer adhesion was very disappointing in the first place.
In my proprietary test setup, most PLA and PETG filaments break around 150-160 N depending a bit on printing speed. The best PETG has reached over 210N. Polymaker PC achieved ~190N without fan and only 95N with 10% aux fan.
This was with a stock 0,4mm nozzle on X1C. I since have upgraded to an E3D high flow nozzle that generally achieves a little bit higher strength which usually stays the same at all speeds while strength slowly declines with the stock nozzle.
So even with the HF nozzle, Bambu PC reached only 158N up to 180mm/s without fan and 135N with the Bambu profile.
Layer adhesion is certainly not the only relevant property, but the only I can measure
For your question it is quite helpful though because layer adhesion is one of the properties that suffer most from too much cooling.
So in summary, if you can avoid high stress in z direction, or mechanical strength is not your top priority, you could probably just use the profile from Bambu.
My test samples that also have some mild overhangs looked just as good without fans, so i will use it with all fans disabled.
Thanks a lot for the detailed answer. I’ll probably try using the default settings once, just to see what happens, and then I’ll try using the same settings I currently have for PA12… There is some cooling, but it’s low.
0% 8sec
5% 3sec
Keep Fan - OFF
I think that would be OK as a start point. May I ask what speed you use for PC printing (basically)? Thank you very much in advance, and then “I’ll leave you alone”
