Need help trying to make a hole bigger

[Richard_Fallon]

I’ve imported an STL file into Sketchup 2017 Make, and it’s not behaving like I expect. The model is of an object I’m trying to print on my 3D printer. The problem is that my printer tends to make holes slightly smaller than they should be, so if I need an exact fit, I have to make them slightly larger in the model. However, in this case, the model is something that I didn’t design myself, so I’m trying to make the holes larger after-the-fact.

I know how to use push/pull to make a hole from a circle. I also know to use Intersect Faces → With Selection in order to properly “carve out” the whole from an irregular surface. But this technique is not working for me.

The model is here: Makamaka_left_end_I2.skp (208.1 KB)

Here’s a view of the semi-hole that I’m trying to widen. You can see the circle at the bottom.

My idea is to extrude the circle into a cylinder until it touches the opposite side, and Intersect it with the model, and then delete the cyclinder, like this:

The problem is that no matter what I do, I can’t delete the cylinder without screwing up the rest of the model. I’ve been trying all sorts of things for the past hour and I’m befuddled.

[Box]

I’m on my phone now so can’t look at your model, but if it is the same one I looked at earlier you are probably having problems because it is very small.
Have a look at using the dave method to make things large enough to work with.

The Dave Method

The Dave Method is the clever use of components popularized by @DaveR to avoid the tiny face issue. Sketchup fails to form faces when edge segments get down around the 1/1000" mark. However, tiny faces can exist so the workaround has generally been to scale up your geometry, edit it, then scale back down. This works, but can lead to some issues. The Dave Method leverages the power of components to make life easier. The basic concept is, you start with a component set at the size you want, t…

[Box]

Made it to a computer, not mine. The dave method is still relevant but I didn’t need it to do this.
I’ve moved the circle down to the face using the up arrow to lock the blue direction.
The rest is pretty self explanatory.