I noticed that occasionally when I rotate an element, it rotates by 18 degrees. Is there any reason why this happens, and is there a way to make it work in minecraft?

I am trying to create a gear model. But even using the arrow keys, I can't center the diagonal spokes.

I've searched everywhere to try and find an answer, but I can't seem to find one.
If anyone knows a way to more accurately move elements, I'd love to know.

Here's a video showing my issue ...