Hi there?i am have read your description with carrefuly,i very interested with your project,i can help you for make 3d modelling your part bracket to hold tablet.i can send format file you needs as STL,STEP,STP,IGES,and etc,i using solidwork for do it,,please share detail your part and dimension,i will send drawing with good result and hight quality,i hope we can work togheter and i very happy if can help you,thanks Dedy.e