All my models are free, but please consider supporting me if you find my work useful: http://paypal.me/Stu142. It would be 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 editing the file here: https://github.com/Stu142/Freecad-Gridfinity-dimension-variable-editing
Based on the Gridfinity Standard.
This is a FreeCAD version of the Gridfinity baseplate that you can edit to make your 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
The author remixed this model.
The geometry is the same, but the system for editing the dimensions has been changed and simplified with an included guide. The equations used for the creation of the model allows for more dimensions to be changed without breaking the model.