Support settings
Hi all,
I would like to know if it is possible to remove/switch off the support marked as a black circle in the attached picture? This support is very weak and often breaks making a mess in the printing models. I try to change a support pattern but still, it breaks. Any suggestions ho you deal with it?
In addition, how to make the circle more round in Z direction? They always come out more as eclipse than the circle.
Thanks for any hints.
RE: Support settings
First the question of hole circularity in the z axis, the only way to improve it is to use a thinner layer height. As the model is made by stacking layers you cant avoid the granularity of the layer thickness. Its usual to post process the holes and ream them out with a drill bit if you need a perfectly circular hole. The other option is people design the holes in the model such that the top/bottom is not circular but has a slight triangular shape (like a house roof) as this is easier to print in layers. That technique works if you need the hole clearance for something like a screw or bolt but doesnt help if supposed to be visible.
As for the support, at the moment the only thing you can do is to turn off automatic supports and use a support enforcer in the hole. Even then you have to adjust the size carefully of the enforcer and reslice, adjust/reslice until the supports are as you want them as the algorithm used tries to extend past the supported area to make it more stable, even if in cases like this it causes more issues. There are several issues over on github referencing this problem already.
Another option is to design in thin support structures into the model where you want them when its critical and that way you get control of whats printed.
If that's not your original model you could always turn off supports in that area and add one or more small modifier part(s) to the hole to provide the support.
RE: Support settings
Dear @neophyl thanks for the fast and detailed replay. For the holes, I am a bit disappointed because I have another printer cel-robox and the holes are much better in Z directions as well the support itself. I think it is more slicer itself that the resolution. However, I was expected to have an option to compensate for it in Z direction. Something like elephant foot compensation in advance settings. Anyway, thanks again for your answer.
RE: Support settings
I wonder if the the tearing away could be reduced/eliminated by turning the model 90 degrees on the build plate so that the acceleration is in the direction with the most rigidity?
My solution for holes is to increase the number of perimeters and then drill or sand them. For my stuff that is close enough.
Jerry
RE: Support settings
I have just attached the result from the cel-robox (the attached picture). The same resolution, 5mm hole. Even without proper cleaning, it looks much more round that from MK3S. I think, the propose of 3D printer is to use as least as possible additional tools.
I did not want to lay it down. As you can notice, there is a T-slot. It is better and cleaner to print in this direction.
RE: Support settings
Have you actually printed the prusa sliced version to compare the actual output ? Previews by the slicer can sometimes vary from the reality. Id cut the model down to just the hole being printed (cut at z height and then a few modifiers with 0 bottom/top/perimeetrs/infill) and slice/print just to see what you actually get.
The one you picture looks very rough to me with lots of strands of filament sticking out from the edges. I've had 3/4/5mm holes come out looking much cleaner than that when printed in Z.
RE: Support settings
@kamil-c
I was not suggesting you lay it down just rotate the part so the long axis of the print is parallel to the movement of the build plate.