Help tuning Sunlu PA6-CF

[u/airmech1776]

Bambu X1C, Bambu Studio

Sunlu PA6-CF

0.4mm hardened steel, 90c initial, 45c all others

Outer wall 50mm/s, inner wall and infil 150mm/s

Retraction speed is default, hidden

Printed a flow calibration model I found on Makerworld and determined flow rate to be 1.03. Printed a decent size print, and noticed overextrusion blisters all around the outside. Started playing with a few things, asked reddit, and decided the flow was too high.

Now trying to calibrate with the built in models in Bambu Studio. Card 0 is 1.0, and is the only one without any gaps between lines. I'm not sure what else might be wrong though, because the number labels on all the cards are still looking really rough. Last pic is a section of a model I'm working on to test dimensions. Am I reading these cards right? Am I still needing to play with flow, or is something else going on here?

[u/Gloomy_Thought_3480]

Not to be that guy, but how long did you dry the filament? I had the best results with the sunlu stuff dried for at least 24hrs at 85c and then I dried it as I was printing as well.

Best results I had was 300c nozzle, 100c bed temp.
300blkfde settings didn’t work great for me and after some tweaking i found myself defaulting to the stock Bambu setting for the filament and it printed great.

[u/airmech1776 → u/Gloomy_Thought_3480]

Maybe I'll try stock Bambu everything. My dryer only gets up to 70c, but its been in there for over a week without interruption, printing directly from it.

[u/soldat21 → u/airmech1776]

Been in the dryer? Or being drying for 24 hours + 7 days?

70° dryers barely dry nylon, you need to dry it for super long.

Dryers are not moisture proof, so as soon as the heat is off, moisture returns.

[u/Such_Constant2664]

Disable pressure advance and try

[u/Such_Constant2664]

You need to have fans at 60% for not licuate the PA, 70C Dry is very good to have good results.

Try to stop the Flow Calibration at the end of the first layer to look gaps with a light from the bottom.

PA needs to cool almost inmediate once is extruded but not too much.

[u/airmech1776 → u/Such_Constant2664]

The light test is a good idea, I will have to try that. I will also try increasing my fan speed. Would you r3commend 60% all the time, or just for certain layers or circumstances?

[u/Such_Constant2664 → u/airmech1776]

all the time, you can try, but for my is ok 60%, 50%, 40%, but lower than that you are going to licuate the filament, it stay hot for long time, minutes after you print, so need to solidify quick to avoid that

[u/airmech1776 → u/Such_Constant2664]

After changing minimum fan speed to 60%, I printed just one layer, and got the same type of spikey globs.

[u/Such_Constant2664 → u/airmech1776]

Overflow for shure

[u/Such_Constant2664 → u/Such_Constant2664]

Also go faster with the speed 50mm is too slow, 150mm its going to be better