Solid Inspector 2 problems with such simple objects - going crazy

Hi all, sketchup newb here. Long story short, I have been trying to create a solid per conveyor belt so it can be ready to be 3D printed as an STL file. However, I am still seeing errors on Solid Inspector2.

I cannot get my head around something that seems so straight forward and I am going crazy. This is for a uni project and I should be lazer cutting already. (see attached .skp)
conveoyors for 3d print.skp (9.4 MB)

This is inside the sides where the rollers would sit, I don’t see anything wrong and Solid Inspector won’t automatically fix it.

All I want is to add working rollers to the straight and curved rails/sides and to make them solids so it can look like conveyor belts ready to be 3d printed.

Please assist, I really need it.

You need to group the geometry of one straight conveyor belt. Then inside that group select all > ‘Intersect Faces with selection’. Finally delete all circular faces inside the beams. They show in your second screenshot and are the culprit besides not working with a group.

This is what I get:

p.s. Do you really need rollers consisting of 90 facets.
Wouldn’t 48 or even less, 24 facets be enough for 3D printing?

Thanks, this solved the solid problem. Just one more thing which I’m stuck on; Is there a tool to create a curved beam like this and have those rollers on there like the straight conveyors? The curve I have now is messed up as its missing some faces and I don’t know how to satisfyingly spread the rollers in the same path as the curve.

In regards to the 90 facets, yes- I’m aware that there is too many for a simple 3D print and will reduce this amount. Thanks again.

I answered that in your other thread on the same subject.

I did not notice, I’ll have a look.