Not so fast on drilling the hole! While your model is a “solid” in terms of ability to 3D print, it is hollow inside!
So any hole you drill will cut material for only the thickness of the walls. If you need a hole THROUGH the part, then you’ll actually be drilling two holes - one as the drill enters the part and another as it leaves. In between will be no material.
If this hole will be taking a fastener that applies ANY pressure, tightening the fastener will distort the part!
There are a couple of solutions:
- Add a hole with material surrounding it. Diameter of the hole is desired diameter of finished product. If, due to shrinkage/expansion of material (which depends on the printing process and material you’re using), the hole ends up too small, then you can drill it out. Surface quality of the inside of the hole is something you’re not likely to care about - as it will be hidden by the fastener!
- Add an interior post with a large enough diameter such that, when you drill through it, there’s enough support material after you drill to resist the compressive force of the fastener.
If you’re printing yourself, you need to pay attention to the details your slicer program presents. In case #2, your slicer may want to make the interior post as a solid edge with a “filler” pattern within it’s bounds. You don’t want to drill through the filler pattern - it’s not solid! In case #1, your slicer program will apply the filler inside if the wall is too thick.
If, on the other hand, you’re having it printed by a printing service, you have no control over the slicer. Here, I’d recommend case #1 as the service’s product review will most likely recognize that the hole might have a compressive fastener applied to it and will make sure the wall thickness of the hole is OK.
Perhaps a picture will help:
Note that I use RED for my “inside” face color.
The cube (with parts hidden by section plane) on the left shows case #2
, the cube on the right shows case #1
Here’s the .skp file if you want a closer look: Two Holes.skp (59.1 KB)