Hi, i just read your project description and it sounds very interesting. I'm Hermann an electronic engineer with many year of experience, I have great experience with marlin, grbl and arduino as I used them to build diy 3D printer and cnc machines and many other projects, you can check my youtube channel to see that. I have all the parts in stock so, I will test your code before delivery. Please get to me inbox let's discuss the details of your project. Thanks