Hi everyone!
I recently bought a Bambu Lab P1S with AMS and started doing some tests using PLA.
I’ll be using it mostly for work, but also for some personal projects.
Here’s the issue: when I print parts with holes perpendicular to the print bed, the result is pretty good. There’s a dimensional error of a couple of tenths of a millimeter, but I think I can fine-tune that.
The real problem comes when I print holes parallel to the print bed — they come out as ugly, misshapen ovals.
Does anyone know how to fix this issue?
The short answer is that this is best done in CAD by creating a triangle at the top of the hole where one expcts there to be droop. This is by far not perfect but it is one of the best-practices items you’ll find in tutorials on “How to design for 3D printing”.
Now having said that, one can do this to a small albeit clumsy degree in the slicer using negative shape modifiers and adding the triangles that way.
I will create an “extremely exaggerated” example for illustration purposes. Normally the height of the triangle would be less than 10% of the radius of the hole diameter but this will illustrate how one would do this in the slicer. As stated, best practices dictate doing this in CAD.
Steps:
Create a triangle that is the width of the hole but where the tip protrudes 10% of the radius of the hole.(Exaggerated in this photo.
Select both objects to create an assembly. This will allow you to suspend the triangle object in mid air.
Move it into place
Right click on the triangle or select it from the objects menu.
Right Click and change the object type to negative which will act as a knife in the part.
If I’m designing the part, I’ll sometimes use a hexagon instead of a circle for holes on vertical planes. If you orient the hexagon so one point is on top, it won’t even require bridging.
I’ve done the hexagon trick before and that has worked but dependent on the desired use.
Have you tried printing a test using supports. I’ve used supports and they have popped out very easily.
I’m working on a model right now that has several deep holes that have printed just fine. Not parallel to bed but not far off and they have printed well with no support.
There is a feature baked into Orca Slicer called polyholes which achieves something similar. The concept has been around for quite some time as described in this 2011 blogpost. I did not include it originally because it is a really advanced topic and if you don’t know how to use it–which I clearly don’t–it can produce unusual results.
Thanks everyone for the quick and numerous replies!
I’m a bit puzzled — an old Anet A6 with an outdated slicer like Simplify3D didn’t have this kind of issue… It had plenty of other problems, to be fair, but I thought this would be an easy one — turns out it’s not.
I’ll try printing some hexagons and see what happens. Stay tuned, I’ll keep you posted!
