Understanding Wall Order

Bambu Lab A1 Series General Discussions
1

Hi All

New user, been having fun with my A1 for about a month, learning a lot. Starting to get some consistent quality prints but was having random defects in the outer layer, so after watching some video I thought I would try changing the wall order. Outer layer first gave me AMAZING results, but it has a few defects that seem to be based on my setting changes, help me understand why.

Bambu PETG Gold filament (was opened a week ago, dried 9 hours at 65C before this print)
A1 with AMS Lite
0.4mm Hardened Steel hotend

Using the 0.16mm High Quality Profile with Outer/Inner wall order, outer walls slowed to 50 mm/s
I also changed the Travel Distance threshold from 1mm to 2mm (as recommended in some random video). I have already removed this option.
Don’t cross build area enabled
Gyroid infill
Default Seams

So basically I’m just trying to understand why this is happening, and is there a way to fix this by changing some settings? Or will this always happen on this print because of the way the design and slicer paths?

TL DR

It appears the defect follow the seam line. Can you help me understand why these settings are causing these defects?

print
print1258×1898 153 KB

print2
print22732×1976 398 KB

print3
print31078×1152 202 KB

Thanks in advance

2

To me it seems like the tip of the hotend is dragging after the seam for some reason because the path that was determined by the slicer

So filament has been drying all aft. I’ve removed the Travel Distance threshold edit, I’ve also set Scarf joint seams to contour.

and I’m re printing the problem area to see if it makes a difference.

3

Those setting changes made no difference.

print
print2294×966 280 KB

Going back to Inner walls first… Will report back tomorrow

4

Printing Inner walls first helped a bit, there was less dragging on the outer wall, but more on the inner wall.

Last night I tried again using info from this thread:
https://forum.bambulab.com/t/a1-nozzle-dragging-on-print-causing-failure-using-08-fine-resolution/

Changed:
Z-hop type to Normal
Travel distance threshold to 0
Unchecked Reduce infill retraction
Normal seams (no scarf)

I also moved the seams to the back of my build and there is a tiny bit of scraping by the seam, but it’s almost nothing, so happy with theses new settings.

Would still like to understand mechanically why this is happening so I don’t have to, print and tweak each time, but at least this build is good…