Well the truth is NEVER!
In my months of being a front-end developer, I've had issues on deciding when to start taking on new projects and or learning a new framework, language, platform or any other thing regarding going forward.
I'm highlighting this because I know that many of us face with problems like this. My best advise is to just start because if you wait for the right time, you'll never get it done.
IF NOT NOW THEN WHEN