Drill press lock and stop nut - GIF

[Frank S]

I'm wondering if we can't cheapen up this design a bit. What about replacing the drilled nut with a castle nut? That would save a fair bit of fabrication time.

No reason a castled nut wouldn't work. it would be limited on fin adjustment but that may not be a huge issue for many operations. I personally like a spring-loaded quick nut, and setting my milling cutters to a predetermined depth in the collets, but that's just me