This is a whole Scrabble set I designed and made to be used for replacement pieces or to build your own set from scratch... Here's a video explaining how to set the pieces up for dual extrusion and explains the difference between my three different designs... https://www.youtube.com/watch?v=AxjSmcHZi48&feature=youtu.be The dimensions are 19x19x4 which is the standard scrabble piece size... I have 1 design for dual extrusion which takes to STLs... "Dual_Letter_X" and "Dual_Shell_X"... I explain in the video how to print them if you're not familiar with dual extrusion... I also have two designs for single extrusion... One with a cut in where the letter is and another with extruded letters so you can make a Z stop at 4mm and change filament to a different color... Everything else is self explanatory.... If you have an questions or comments, feel free to leave a comment or message me directly... Enjoy!!! Watch the video.... Also, here is an Instructables... http://www.instructables.com/id/3D-Print-your-own-Scrabble-Set/