Thumb screws are so that in case a fan fails it can be removed easily without tools . I know it may not be ideal abs maybe prove to be the least best choice but that was the direction I wanted . I could use nuts with nord lock washers or even just some washers and nylon nuts just not as nice...
I am looking for some good videos online regarding simulation analysis of a fan. A bit about the fan DC Fan Ball Bearing 220MM 48V 103W 6500RPM (PABST 2218F/2TDH) . There would be 10 mounted to a fan panel. Each fan itself would be mounted to its own smaller square plate using 4 x M4 nylock nuts...
