Problems making a hole in a hollow cylinder

Discussion of the topic “Sketchup Many components in the list of components in the tray” showed that the level of knowledge of the participants in this forum is very high. Therefore, when I had another problem, I again decided to seek help here.
I have a distribution box model in which I need to make 4 holes with a diameter of 14 mm. To do this I used the Split tool from the Solid Tools panel. There is a solid Junction Box component and a solid group (cylinder with a diameter of 14 mm), with which I make the hole
After doing the Split operation and removing the cylinder, I can’t see the outline of the cylinder on one side of the inside surface of the box.
Accordingly, I can’t make a hole. Why is this happening? Moreover, when I tried to change the diameter of the cylinder (as far as I remember, I made the diameter 12 mm), everything worked out.
I am attaching the model
JunctionBox.skp (129.8 KB)

You split the cylinder with the wall of the box. And you left the geometry for the holes. Wrong order of operation and wrong tool.

Instead of using Split, use Subtract or Trim. I’d use Trim for the first pair of holes, rotate the cylinder 90° and then use Subtract.

Part of your problem, too is that the cylinder is laying on the floor inside the box. Move it up a couple of millimeters and you won’t have the issues associated with the tiny geometry.

1 Like

Does not help. Here is the result of using Trim

Only one hole and after use Subtract

See my edit, above. It works for me after moving the cylinder very slightly up so it doesn’t intersect the edge of the floor in the box.

Are you planning to 3D print the box?

Thank you very much Dave. You’re right. It is necessary to reduce the diameter to 6.5 mm and everything is fine

No, I don’t plan to

Following on from what Dave has shown you, it it often best to work using the origin as a center point, this allows for simple accurate arrays around your circle.
And a solid group can contain separate elements, so as you see here a simple array/group/subtract.
GIF 10-04-2024 10-54-50 AM

By the way, in Model Info/Units you have Length snapping enabled and Angle snapping disabled, I would suggest you reverse that. Length snapping can produce tiny errors in your geometry and Angle snapping is useful as it makes arrays and things easy to snap rather than having to type 90 etc.