this is printed with Airwolf3D XL, ABS, 0.2 layer size, 240 degrees Celsius extruder temp. What parameter should I tackle to get rid of these cracks? any advice?
There are no parameters to control that, What you need to do is control the environment (not too cold, no drafts over the printer) to keep the ABS from cooling to quickly after being printed.
I don’t know the Airwolf, but on my Prusa something like that would be caused by the Z steps at 0.2 layer height not resulting in an integral number of steps. E.g 312.2 instead of 312. If you change the layer height does it change?
well usualy, in my lab, when I leave it for night, it’s cool, but yesterday i had a climate control on, and it was 27°C, I thought about the fast shrinkage too, I will try to print with 0.25 tomorrow, thank for your comments
What @Whosa_whatsis said. Also, layer adhesion may improve enough to prevent splitting on this part at lower layer heights. 0.2 layers with the 0.5 nozzle is not unreasonable, though. I would try 0.15 next instead of 0.25. The ultimate problem is cooling though.
ok, I’ll try 0.15
Build a box to go around the printer, it doesn’t necessarily have to be actively heated. Sometimes the build plate heat is enough. Just make sure your electronics and such do not get too hot.
On the plus side this means your prints are sticking to the bed quite well…
Sometimes, you could be under exuding just enough to have incomplete adhesion. Make sure you start with a good calibration of your e steps.
I am with @Joseph_Chiu sometimes your extruder is not working well all the time (mine was occasionally binding, because of aging gears, and losing some steps every now and then). If the problem is small, it may not be easy to pinpoint.
I am more in favor of drafts, irregular cooling and even humidity. I have experienced a couple of those artifacts derived from drafts that made the layer cool faster that the rest.
@F_Malpartida_fm , it’s true, even when everything is right with the machine, large ABS prints are a fight with cooling until you can keep them warm. But you can get pretty far by fixing problems that smaller prints tolerate.
I was able to completely get rid of those cracks with abs by building a plexiglass box around the entire printer. If you do it, make sure that nothing on the printer is getting to hot.
Heated build chamber. It’s cooling and shrinkage causing cracking. You have to keep it pretty warm to prevent cracking.