eSUN ABS+ print distorting at base

Bambu Lab P1 Series Troubleshooting
1

I’ve been using various PLA filaments with good success so I thought I would try using ABS as I need to print something that will be in direct sunlight a lot.

I first tried printing a few small parts and these came out well. I’m now trying to print some essentially large boxes 250mm x 115mm x 10mm. The first attempt I printed 2 of these with the largest side flat on the bed, this did not come out well, the first and last layers had an over hanging lip, but more importantly everything on the outer edges of the bed bent upwards during the print causing the piece to be curled up along 3 of the edges, this then caused the top layers to get messed up as I assume the print head was pushing into the top of the print.

I then thought it may be better to print these on their end, 250mm x 10mm side on the plate, and while this came out much better I still have quite a bit of deformation. If I put one end on a flat surface and hold it down the other end is 5mm off the surface, its is the side that was on the baseplate. The vertical sides have a slight concave deformation, the top and bottom protrude further oud than the middle, but only by 1mm or less so this is less of an issue.

I know that ABS is a more tricky material to print with than PLA and I guess I am going to the extreme or trying to print something straight and flat that it half of the area of the print bed. But I am hoping I might be able to get a bit of a better result after tweaking some of the print settings. The trouble is I don’t know what settings to change.

I am using the eSUN profile I downloaded for bambu printers from the eSUN website.

I am guessing the issue I am seeing is that the material is shrinking as it cools which is mostly along the print bed. I’m not getting any other issues with the print. If anything I’m seeing a little too much bed adhesion, but nothing major (don’t have any glue sticks yet though).

What setting(s) would you recommend I change?

P1S Printer, 0.4mm nozzle
0.2mm standard @BBL X1C
wall loops 2
top shell layers 5, 1mm thickness
bottom shell layers 3, 0mm thickness
infill pattern rectilinear
sparse infill 15%
pattern grid

Filament settings:
nozzle 260c
textured plate 100c
no cooling for 3 layers
min fan 10% 30s
max fan 50% 3s
keep fan on true
slow printing false
force cooling true
aux fan 0%

Print file
solid.3mf (24.3 KB)

Thanks for any help

2

ABS takes quite a bit more to print well compared to PLA. Especially larger ABS parts, as these tend to warp much more. The issue is that ABS shrinks as it cools and so you have a temperature gradient between the bottom layers and the upper layers, which sadly results in warping.

As a first step, you should heat soak your chamber before starting your print. Turn on your heat bed to 100c and your aux fan to something like 50%. Leave it like that until the chamber reaches 45c+ and then start your print. Do NOT open your door or turn on the chamber fan while printing. This will help keep the temperature in the chamber at a more steady rate and reduce the chances of warping.

I don’t personally like brims, but adding one will also help keep the print stuck down and reduce warping. It gives it a larger surface area beyond the print to hold down to the build plate. I’d suggest using a brim width of 8+.

Some other things to consider, is that you need to make sure your bed is clean by washing it with hot water and dish soap. You want the best adhesion you can get and a clean bed is the way to go. You might also try adding glue to the bed to help promote better bed adhesion.

The Bambu wiki has good info out there for all kinds of printing issues. You should take some time checking out the site.
Here’s a couple of good ones to read for your issues:

https://wiki.bambulab.com/en/knowledge-sharing/common-print-quality-problem

3 Likes
3

Thanks for the suggestions. I tried preheating like you said, added brims, washed the bed even though I was pretty sure it was clean anyway, I also changed the infill to Gyroid as the wiki said this can help. I also positioned the piece diagonally across the plate to see if that helped.

Obviously I don’t know what out of these things worked or if its a combination of them as I made all the changes together.

I’ve managed to reduce the warping at the base from 5mm down to 3mm, the sides are about the same as before, I think this is caused by the base warping.

Do you think there is anything else I can do to reduce the warping further or am I at the point where I’m not going to get much better with the size of the piece I’m printing?

I have wondered if PETG (or something else) would be a better material to use, It doesn’t need to be particularly strong, UV resistance is my main concern along with print accuracy.

4

You can try other 3rd party steel sheet, especially the black textured PEI sheet. Some seller on aliexpress sell them as “Textured Pro”.

I find out that the black textured pei sheet (aliexpress) is more “stickier” with ABS than the yellow one (aliexpress). The yellow one is better for PETG and PLA than ABS.

For me, my first ABS print with original bambu textured plate did leave permanent mark on the plate where the part touch the plate. the second print of the same thing welded to the pei coating. When I removed it, the part broke apart leave the few first layers on the sheet. After that I put away the original bambu textured plate and just use aliexpress plates

Btw, ABS will change color and become crumble + brittle after exposed to sunlight UV for a few weeks. PETG can withstand UV but becomes soft at 70degC while ABS becomes soft at 90degC.

You should use ASA instead since it can withstand sunlight UV no problem, have the same mechanical property as ABS and become soft at higher temperature of 105degC while shrinkage is slightly lower

2 years ago, ABS filament is cheapest among PLA, PETG since enclosed printers were not popular, but now it is more expensive than PLA. So my choice now is PETG or ASA if used in hot environment.