Poor print quality using PA-CF

Bambu Lab X1 Series
1

Posting this here as no luck on FB forum:

Continuing to have problems printing in CF on my X1 Carbon. Bought a filament dryer and that seemed to resolve print quality. However, the boom in the photo on the right (about 3/8 diameter) is terrible. The rest is all good. Prints great in ABS (left side one). Nozzle is 0.6, wall loops: 3, top surface: rectilinear, sparse infill: 50%, sparse infill pattern: honeycomb are the only changes I made for CF.
IMG_3983

2

I saw replies to you on FB. It has to do with “time on layer”.

1 Like
3

Time on Layer for sure! One way to prevent these blobs is to create a small tower in the opposite location of this part of the print bed so that the layer has a chance to cool.
The other thing you can do is to slow the print overall…

4

Yes but where do I find ‘time on layer’. I’ve spent 2 hours on this today and cant find it. Very frustrating. Everybody is saying ‘time on layer’ but when I ask ‘where and how’, it’s crickets.

1 Like
5

I’m not at my computer. You can try slow down for overhangs maybe? What speed setting are you on?

6

It’s in the filament profile, Cooling tab. Hover over the options to see what to set. You’ll probably need to increase max fan speed.

Screenshot 2023-02-12 191455
Screenshot 2023-02-12 191455736×593 27.3 KB

2 Likes
7

Done that too. Slowed overhangs to 10mm/sec. Made a bit of difference but not enough. At the end of the print, even though it’s going considerably slower on the support rod, I can see roughly 1/4" of material directly below the nozzle moving around as the print head prints. Clearly it’s too hot and layers haven’t had time to solidify.

8

Thanks for that! Talk about it being buried away. Here’s my settings:

Screen Shot 2023-02-12 at 5.00.52 PM
Screen Shot 2023-02-12 at 5.00.52 PM747×670 47.2 KB

9

Well, yeah, that’s the same as Generic PA-CF. You probably want to increase Max fan speed threshold to 50% and at least 5s layer time.

1 Like
10

Doing that now and printing. Will report back in an hour. BTW, THANK YOU for pointing me in the right direction.

11

Success! Thank you again. Now to the next CF print I had trouble with prior to buying a dryer.
IMG_3990

3 Likes
12

Those do not control layer times, those just control fan speeds. It increases fan speed between those layer times, but it does not slow down printing. To actually slow down printing, you also need to set the “Min print speed” to much lower value.

13

@zviratko , layer time IS controlled with the two options I mentioned. Hover over the “Slow printing down” item to see more details.

@GarysGarage , great news!

1 Like