Some good news from the Tinkercad team. We've heard a lot about the grid and the chance to match its size with 3D printers.
Let me introduce you to some new options on the Grid. Just above the Snap Grid settings, you will now see Edit Grid.
What this does is open a dialog box where you can define units (mm and inches for now), and also select a 3D Printer. As you change the printer, you'll see how the size of the grid changes accordingly.
Now, when you use the grid as a workplane, we also wanted to differentiate it, so we kept the 200x200mm grid.
Let us know what you think about it (and say thanks to Petr Broz and Darin Hughes for this feature if you see them around).
If you want more printers to appear there, we'd love to understand what you are using.