SketchUp will only provide calculated volumes for objects classified as solids. The easiest way to get a solid is to add the faces to a group. If you make a hole on a single face within the group, it can't calculate the volume any more. If the group is a solid, and a 'through hole' is made using the push/pull tool, then that should still work.
If not you can try this plugin: http://sketchucation.com/forums/viewtopic.php?p=16067#p16067
If not you can try this plugin: http://sketchucation.com/forums/viewtopic.php?p=16067#p16067
Why not use simple math to subtract the bracing from the box? There are several ways to work around a hole. You could either work out the volume of the rectangle and subtract the circle, or more simply click of the face of the rectangle with the hole in it to get the area, and multiply it by the the thickness.
SketchUp will only give the volume for completely ‘sealed’ objects inside the same Group or Component. If you make a ‘hole’ in any of the Faces, it cannot determine the remaining volume.
This is because SketchUp isn’t really a CAD tool as they’re typically known. It’s a polygonal surface modeller with some features for editing the lines which make up each surface. The easiest way to see this is when you make a ‘circle’ - you can see the edges that approximate a circle shape if you zoom in. That means that a cube in SketchUp is made up of six Faces around an empty space. It also makes editing or working with existing objects quite difficult, especially once they become complex.
Most other CAD tools have these features but create Solids - either once surfaces are joined together at the edges to enclose a volume, or by dedicated tools which combine or subtract simple 3D shapes from each other. That means they can give the volume for a complex shape because it has ‘stuff’ inside it.
While SketchUp is great as a free tool and has a huge number of videos or guides available, I quickly butted up against limits like this one. I’d recommend moving to more full-featured tools like FreeCAD or Fusion360 which are available for zero or very low cost. Being able to work parametrically is a huge benefit, and the models are more compatible with other tools to boot.
If you’d like to keep a SketchUp-like workflow or are a pen & paper person, then I’ve also been having a lot of fun with Shapr3D for sketching out ideas quickly. It’s amazing on iPad or Windows tablet with a pen.
This is because SketchUp isn’t really a CAD tool as they’re typically known. It’s a polygonal surface modeller with some features for editing the lines which make up each surface. The easiest way to see this is when you make a ‘circle’ - you can see the edges that approximate a circle shape if you zoom in. That means that a cube in SketchUp is made up of six Faces around an empty space. It also makes editing or working with existing objects quite difficult, especially once they become complex.
Most other CAD tools have these features but create Solids - either once surfaces are joined together at the edges to enclose a volume, or by dedicated tools which combine or subtract simple 3D shapes from each other. That means they can give the volume for a complex shape because it has ‘stuff’ inside it.
While SketchUp is great as a free tool and has a huge number of videos or guides available, I quickly butted up against limits like this one. I’d recommend moving to more full-featured tools like FreeCAD or Fusion360 which are available for zero or very low cost. Being able to work parametrically is a huge benefit, and the models are more compatible with other tools to boot.
If you’d like to keep a SketchUp-like workflow or are a pen & paper person, then I’ve also been having a lot of fun with Shapr3D for sketching out ideas quickly. It’s amazing on iPad or Windows tablet with a pen.