My eyeglasses fell off the shower door one time too many, so introducing this shower shelf, sized to easily hold eyeglasses. 

As shower doors vary in width, the FreeCAD model is included.  The ShowerDoorDepth value in the params spreadsheet allows you to change the width of the door.  The default is 15 mm.

Also included one STL that uses the default door width of 15 mm.

I tried printing in ASA and PETG but both had a failure, a clump built up in the middle of the shelf, the same spot on both types of filament.  The BambuSlicer showed a Gap Infill in the failure region.  Rotating the model and reslicing removed the Gap Infill and the model printed fine in PLA Tough.  

Finally I printed using manual supports for the door arch.  No need to support all the little 5 mm hexagons…