Thanks for your replies! I created a load of cuboids (I have them saved as groups as well, don't worry) to make this model. I'm currently trying out the 'Outer Shell' tool, but I'm getting errors saying that some components are not solid/locked? The file is available at https://livenorthumbriaac-my.sharepoint.com/personal/w15020866_northumbria_ac_uk/_layouts/15/guestaccess.aspx?docid=1365896736bce4ba4a568b0c78e25066d%26amp;authkey=AScBAXTks0RE9vN2UgLiZpU

Hi guys, I'm trying to create an intricate product on sketchup for 3D printing. I've done it by intersecting a load of cuboids, and I only want to keep the faces that are visible from the outside, because the cuboids all have parts inside the product.

The file can be found at:
https://livenorthumbriaac-my.sharepoint.com/personal/w15020866_northumbria_ac_uk/_layouts/15/guestaccess.aspx?docid=131d63f744fd645be9f0ee6613862c9ee%26amp;authkey=AbS_5XzPCJkUHR-HiF-K5FE