Bookshelf organizer

This is a bookshelf organizer consisting of a main book-sized body and a separate exchangeable plate with letters or a category text that slides into the main body. The organizer is placed in the bookshelf for a clear overview of where to find which books.

The original design is sturdier and gives better support to smaller and thinner books, but since it uses quite a lot of material (85 grams), I mainly used the slimmer design that cuts the material needs with a factor of 2. My shelves swallowed 42 organizers, so saving material seemed like a good idea...

Use either the letter object with the letter plate or the text object with the text plate and slide it into the pocket in the organizer.

Customize the letters and texts in the FreeCAD file (7 letters can be placed above each other, I moved letters currently not in use 1 m along the z direction to keep them out of the way). Depending on the content, the letters and text may need some adjustment of sizes and positions. Export l