For what seemed like the longest time, baby boy was only napping for exactly 45 minutes. It was like clockwork. We would joke that we could set our watches by his naps. It was so annoying because 45 minutes is not enough time to get anything done or take a nice nap myself.
But finally, he is (fairly) consistently taking one or two 1.5 hour naps and one 45 minute nap, and it feels glorious!
I didn't do anything differently to get him this way, which only reinforces my belief that babies will do what they need to do when they need to do it.