About this 3D model

So I wanted to participate in the 3D Printing Nerd Challenge to design a filament spool hook for his filament rack so that he can take out a spool out of the rack, and print directly from the filament rack. So I designed a minimalistic but functional hook which should be very strong. (I have no 3D Printer yet to print and test it) This hanger fits lumber or any material, as long as it is 18mm thick and somewhere around 40mm high.