We needed to create a flat top Duplo piece for a science project where we could glue images to the flat tops. Remixed original by TmnSn, the connection is tight to regular Duplo but loosens with connecting and disconnecting a few times.
Full hight and half height 2x2 models.
Print with flat part on print bed.
If gluing images to the flat part like we were, I recommend changing the base layer print pattern to Hilbert Curve to give a rougher surface for glue to adhere. Worked really well.
The author remixed this model.
Using the same model, removed studs for flat top and reduced height to make a block that is half height with a flat top.