Modifying STL file to add holes. Not sure how to do it



I have an STL file that I’m trying to modify and add 3 circular holes (2 mm radius) in the top to allow buttons through the case. The STL is here:

If I try to remove the circular sections, I’m unable to like I can with a new design that wasn’t an STL. I copied the STL, and I’m aware I could create a new design, but is there an easy way to fix this STL to add holes?


Import the STL into SketchUp.
Prior to import, look under Options button.
There, set the units to Meters to avoid SU’s issues in creating tiny new geometry.

The STL comes into SU as a Component.
Explode the Component.
Make your modifications.
Make it a Component again and confirm via Entity Info that the model is a Solid Component.

Solid Inspector can help you find flaws preventing it from being a Solid.

Scale the model down to real world size and export the STL file.

I imported your STL into SketchUp in the manner described above.
The model has many holes.
It’s not printable unless it’s a Solid; an airtight closed volume.

How to remove lines based on a STL file?

Explode the component? I see that it works, but I have no idea what it actually did.

Thanks for the tips! It’s printing now.


For your interest…

Working with Components in SketchUp — SketchUp Help

SketchUp Training Series: Components


Thanks again. If I wanted to make those holes larger (say 3mm radius) the back part of the hole would be on the slanted part of the case. I tried to do that with the raise/lower object, but that didn’t work as expected.


… and it never will.

In SU you can’t use the raise/lower tool (aka the push/pull tool) on angled, or curved surfaces.

There are two other options for this which both work great, and both are commands that are found on the ‘right clickcontext menu.

1- The ‘Intersect Faces’ command: This command will place an outline along the paths where two objects intersect. and from that state you can manually Select, and Delete, the parts of the model you want cut out.

2- Alternatively the Solid Tools > Subtract command will also do the trick, but in a more automated way.


Option 1 is extremely painful and time consuming. Either I’m doing something wrong, or it’s just not the best way to do it. Even after doing the intersect faces, deleting things to open up the holes still deletes things I don’t want removed.

I tried option two and it was much easier. I just had to deal with the object not being solid, but I was able to resolve those issues with solid inspector. Much easier using the subtract option.