This is a basic musubi press that I modeled up to become better at FreeCAD and to make some musubi. I've included both printable stl files and the original FreeCAD files if you want to make some modifications to the press. The Kanji for “musubi” is engraved into one side of the press so you know which way is “up” when making musubi. There is a slight lead-in chamfer on the top edge of the base to facilitate alignment.
If you do choose to print this for use, please understand that the nature of 3D printed parts is not food safe. If you want to use this with actual food, my recommendation is to place a sheet of plastic wrap around the press parts before adding rice and fillings to keep food contact to a minimum.
The top and base can be nested on the build plate. Optimized for 4 walls with a 0.4mm nozzle and at least 15% infill to get a solid base print and a robust top piece that you can apply some pressure upon.
The author marked this model as their own original creation.