This clock looks very good, I had to print it.
After printing I could not get the seconds dial on the motor shaft. I had to increase it by 3% and it fit great. When I tried to operate the clock it would hang up constantly trying to turn the other wheels. I had a hunch that the stepper might not be strong enough to overcome the friction and force needed to turn all wheels. I found a web page on how to change a unipolar 28BYJ-48 to bipolar stepper motor. It gains almost three times the power! (http://www.jangeox.be/2013/10/change-unipolar-28byj-48-to-bipolar.html). By doing this you need to change the driver. I used a L293D as mentioned on the web page. I also had to change the Arduino program to another that uses the AccelStepper library instead of the stepper library. With this library I used and modified the constant speed example to use a speed of 34.
Now that it is finished and working I am very satisfied with the results.
Good job Victorrr161.
I had to print the numbers with raft to stick to the bed.