All my models are free but please consider supporting me if you find my work useful: http://paypal.me/Stu142. Much appreciated if you do!
Update: Check out my new FreeCAD Gridfinity Workbench for many more options and features: https://github.com/Stu142/FreeCAD-Gridfinity-Workbench
You can find a guide to edit the file here: https://github.com/Stu142/Freecad-Gridfinity-dimension-variable-editing
inspired by https://www.printables.com/model/237486-gridfinity-baseplate-parametric-freecad-file
This is a FreeCAD version of the Gridfinity baseplate that you can edit to make you own sizes or versions. FreeCAD is totally free and open source, download it here: https://www.freecad.org
Gridfinity Documentation to understand the dimensions of the model can be found here: https://github.com/Stu142/Gridfinity-Documentation/tree/main