Overhangs started knocking my print jobs off the bed, luckily this was before I started printing my MPCNC it happened with some cable chains. Overhangs if they aren’t cooled quickly will start to curl upward. After some time the curl gets more prominent and the nozzle hits it and boom the part comes off. Increase your fan speed, personally I use a minimum 75% fan speed after the first 3 layers. It has made a world of difference in all of my prints.
As far as sticking to the bed, I use painters tape and apply a glue stick lightly and wipe it in with a damp paper towel before each print. All my prints stick quite well now as long as the bed stays leveled (really need to install my auto bed level sensor).
And Vicious thanks for the awesome design, I have 8 parts printed so far. Going to have to source 1″ stainless soon 🙂