Here is a single print clock, that has a carefully designed mounting bracket built in so it can be printed with no supports

the inset area of the clock is 57.5mm x 57.5mm wide and has a depth of 17mm. it has been designed around the generic cheap clock mechanisms you can purchase online, but it's your responsibility to check and purchase one that will fit.

This Nottingham Forest Clock is one of many clock designs I have, more can be found here .. Clock Collection