First of all, thank you everyone who has seen this project. More than 1000 views in a week, awesome!
Good news: Arthur Wolf from SmoothieWare contacted me to send me a new brain for Thor... A SmoothieBoard!. This board could be the best substitute for my DIY control board as it's OpenSource too. Can't wait to receive it! I'll keep you up to date ;)
I just finished the video of the assembly. I know that the more details the better, that's why I'll update the assembly instructions with the steps to visualize it on FreeCAD.
Finally, I'm currently working on the kinematics of Thor, I'll make another log with the Forward & Inverse Kinematics and how I solved it.