Hi everyone,
I’m having an issue on all my 3D prints with my Bambu Lab A1. Whenever a model has a vertical wall that ends with a flat horizontal surface, the walls tend to deform/lean instead of staying straight (see photos). i trying on teh Bamabu lab A1 of a friend and i have the same problem, but my setting seems ok and I use hairspray to agood adesion.
My current settings are:
Layer height: 0.16 mm
3 walls
10% Gyroid infill
Brim at the bottom
I use standard PLA (210–240°C) and i print it at 220 degrees
I can’t seem to get perfectly straight vertical walls. Has anyone experienced this issue or have any suggestions on what I should change?
Vertical walls not staying is usually caused by one of these issues: mechanical alignment, slicer settings, cooling/shrinkage, or extrusion problems.
Check mechanical alignment first
make sure the X/Y/Z axes are square and the frame is rigid.
check belt tension
Inspect Z lead screws / rods for bends and ensure Z couplers are tight but not over-estimated.
Review slicer settings
reduce outer wall speed and overall print speed.
enable/adjust pressure advance or linear advance if your firmware supports it
check acceleration/jerk: too high can cause ringing too low can cause oozing at concerns.
For materials like PETG/ABS try printing outer wall before inner wall and reduce top-infill overlap.
Manage cooling and shrinkage
for LPA use good part cooling for ABS/PETG, avoid too much direct cooling and consider a warmer ambinet/chamber.
rapid or uneven cooling can make walls bow or lean, especially on tall vertical surfaces.
Verify extrusion
calibrate flow rate / extrusion multiplier
make sure you’re not over-extruding, extra material at corners can push walls outward.
use consistent, dry filament
If you can share printer model, material, layer height, wall speed, and a photo of a calibration cube. That usually make it much easier to pinpoint whether it’s mechanical, thermal, or slicer-related.
Check out this guy’s tips. He is really good, and his YouTube shorts are very good… if you can handle the accent and detail. Really knows the print settings too well… This film talks about printing the inner walls first and the outer walls last, giving them support to keep them straight… Have a look
Try using rectilinear infill for both “Internal Solid Infill Pattern” and “Sparse Infill Pattern”. This is much easier for bed slingers to print, and it’s just as strong. Gyroid looks cool, but once your model is finished printing, you never see it.
I’ve had a similar issue with PLA on the A1. In my case, lowering the nozzle temp a little and slowing down the outer wall helped quite a bit. I’d try around 210–215°C first and make sure the cooling fan is running properly.
Also, check the sliced preview around that transition. If it’s basically a small overhang/bridge, adding a little support or changing the orientation can make a big difference.
Thanks for the input! I tried slowing down the outer wall and lowering the temp to 210°C as Richardwt suggested, but I’m still getting minor sagging around that bridge area. Should I increase the cooling fan speed in the slicer, or is it better to just add tree supports here? (Using Bambu PLA on an A1).
Bridges can generally have some sagging, depending on the length. Supports would fix that but then you have the rough finish against the supports. A loose loose situation.
Is the second photo as it printed or is the ‘hook’ what was on the print bed? It looks like elephant foot to me. If the top in the photo was on the bed. There is a setting for that, lower print bed temp might help.
