I’m trying to print a large circular object with ASA. This is a replacement cap for a generator that is used for events, so it’s going to be outdoors in the sun and might get quite hot. The dimensions are 249 x 249 x 22.6mm.
The problem is that there is a lot of warping. The bottom surface needs to be very flat, but it has a large curve. The warping happens during the print and it causes very bad print quality on the top surfaces.
I would mainly like to know if I can adjust any settings to fix the warping. Should I adjust some of the temperatures for the “Generic ASA” preset (e.g. nozzle, build plate)? Or is just impossible to print this model with ASA?
One idea is to reduce the thickness of the disc. It was 4.6mm, but I might try printing it again at half this (2.3mm.) I think it should still be fine. And if that doesn’t work, maybe I can just print it with PLA. (But this is going to be outdoors with lots of UV and heat from the sun, so I don’t want it to melt.)
Make sure you’re pre-heating the chamber up to 50c at least. You could try changing to outer-inner or inner-outer-infill and reverse on odd (orca slicer settings).
However, some models are just difficult to print in ASA. I actually find ABS better, because you can create a slurry of ABS/acetone to put on the bed (look up ABS juice). But also, PETG should be fine for direct sun outdoor use.
Looking on the tables on Bambu High Temperature Plate (Smooth PEI) | Bambu Lab EU it looks like the engineering plate is not really recommended for ASA. I would try with the textured PEI plate instead, if you have it – and buy it if you don’t, it’s awesome. (no gluestick required)
But yes, pre-heating is an absolute must and printing slower with less fan might also help (giving the filament more time to cool slowly should reduce the stress in the part).
But also you could try using a “Raft” which this is mainly the only use for one otherwise you’d never use it for any other application really.
Or print a Draft Shield which is a wall essentially doing what it’s name is, shielding a draft from the print process. Any exotic filaments are prone to this which they tend to lift when it comes to sudden rapid changes of temperatures with the ambient or layer temps.
You tend to print slower so as you’re going up in Z the bottom layers are not cooling rapidly and having a large difference (Biggest sign is layer seperation)
I don’t think the poor surface quality is just from the warping. I would also dry the filament and perform some filament calibration to be certain the flow is right.
If the top is supposed to be flat, I would add a wide brim to help hold the part down, If you get the print to finish without warping, let it cool slowly and completely before opening the door.
as mentioned by others make sure that the door and lid are closed and that the chamber is nice an cozy (cozy for ABS/ASA that is) before starting the part print
up the build plate temp to 95-100°C
print a brim with an object gap of 0.01-0.02mm
I guess you are using the engineering plate with the the High temp surface sticker on one side? (FYI the engineering plate is just the coated spring steel sheet without the stickers).
Even with very good adhesion to the build plate you may get warping issues since the part could even lift the build plate itself from the magnet so make sure the chamber temps are kept high, do not open the door during printing and wait for the chamber and part to slowly cool down once the print is finished without opening the door until the cool down is finished.
Get ASA-CF or ASA-GF. I have printed lots of plain ASA and CF. I’ve done all the things to reduce shrinkage/warping. All work - somewhat. The only things that work fully are 1. Mechanically make it impossible to warp with adhesive and clamps 2. Use a CF/GF variety.
If you want to stay with non GF/CF, get Vision Miner Nano adhesive. Nothing else. It will hold your ASA down so powerfully, the magnetic build plate itself will bend if the ASA wants to warp. So, also print small clamps to hold the plate down to the bed. There are many designs out there already.
I’d go with GF/CF. The real reason GF/CF filaments exist is not strength (sometimes a little more stiffness). They exist to make engineering filaments easier to print - less warp, more dimensionally accurate. Even then go with VMN adhesive.
Of course, as others have said, make it warm in the chamber!
I like the SirayaTech CF/GF filaments.
Also consider Tinmorry PETG-GF. Excellent filament, cheaper, still decent UV resistance. Basically no warp. “My Tech Fun” has a great review of it.
