This thing contains the center casing and dials for those generic square clock movements found on Amazon, eBay, AliExpress, etc. The one I modelled it after was roughly 56x56mm in size.

The casing and dials are meant to complement @myersrj's Giant Wall Clock, so please download his thing to get the numbers.

I've only made dials for the hours and minutes, leaving the seconds shaft unused.

The minutes dial is 25cm long, 5cm as its "tail", and 20cm going away from the center axis.

The hours dial is 20cm long, 5cm as tail and 15cm forward to mark the hours.

These sizes work well with a wall clock that has a diameter of 50cm (measured from the center of each number), with each number 5cm in height.

This is perfectly printable on a 200x200mm bed, just rotate the dials 45 degrees to fit. I'd recommend making sure that the objects are rotated in a way that makes the top layer's infill go along the length, instead of zig-zagging the whole way (see Slic3r pic for reference).