The file 'Phone Holder (customizable) 3D Printer Model' is (scad,stl) file type, size is 13.6KB.
The space at the bottom will direct the sound of the speaker into the drivers direction.
Currently the size fits perfectly for a Galaxy S9 smartphone with this transparent case. It is small enough such that the smartphone will not jump out even if it gets very shaky. (This might however depend on the printer used).
Use cable ties to fixate the holder.
phone_holder.scad | 3.8KB | |
phone_holder.stl | 153.6KB |