28BJY48 -ULN2003 with arduino uno 1 rpm

Hello friends
I want to turn the engine 1 rpm to use a wooden gear clock.
The engine is sometimes fast and sometimes slow. I tried the stepperone Revolution code in the library, but it did not work.
Could you help me with the code? Thank you.

Hi, look at the Page HERE

There is a one-revolution example there. It runs for hours and stays in sync.

What are you using as your clock?

How much faster or slower? Each rotation? or is it over time?

Could you be missing steps because of insufficient torque?