I designed an enclosure for the PCB in solidworks and it looked quite good but after 3D printing, its not that great. It is bulky. This is mainly due to a thick PCB (1.6mm) and a tall motor. Since the thickness is 1.6mm it wobbles a little when i plug it in the USB port. The case is snap fitted together. It has an opening for the HR sensor, LED and a small hole to press the reset button.
The NRF module is slightly thicker than the HR sensor, so the area above the NRF module is extruded more than the rest of the area.
In the next iteration i plan to fix these problems and make a slim watch. Also the wall thickness of the enclosure is greater than the button so i cannot press the button. To add some protection i will need to add a laser cut thin acrylic sheet over the OLED.