This video has a detailed inverse kinematic solution for a 3 axis robot and videos of it in action applying the solution. There are also some mistakes that I cover that happened along the way and crucially unlike most other videos the arm segments are NOT the same length.

The code can be found here and is free to use and adapt:
https://github.com/JustAnotherMakerCh...

3D Print files: https://www.thingiverse.com/thing:646...

Music from #Uppbeat (free for Creators!):
https://uppbeat.io/t/dangerlionx/gh...