Ok, some things are a whole lot more complicated than you would think. Engraving for example. The irregularities in thickness of material can be a real pain some times.
I found a guy to make me a spring loaded engraver, and that helped. The tip he used would bend at the slightest hard lip of even a .002. Otherwise it worked fine. Hills and valleys it dragged over just fine. I even used it to engrave some sockets to see how much incline it would climb. (I could make my own now that I have the lathe.)
I wanted a stronger harder engraving tip. I ordered some tungsten carbide ones and some diamond ones. The diamond ones worked great even on chrome and stainless. On aluminum of brass they gummed up. The tungsten ones worked ok, but were just not sharp enough. I wanted a better line with less pressure to reduce gouging.
Of course I was dealing with finding a good way to clamp down some small brass plates at the same time. The brass plates came with adhesive tape on the back so just clamping down the edges didn't work because it would warp pretty badly around the tape. Fine if it were steel, but for brass that was just too much. The engraver would gouge too deep.
Somewhere along this process I picked up a cheap mill vise hoping it would help, but the bolt slots were stupidly large and it was too wide even if I got longer bolts for my t-nuts and used washers.
Finally today it all came together. I drilled and counter sunk the flats on the vise, grooved the jaws, and found a way to sharpen tungsten carbide drag engraving tips on the cheap. I got a very sharp and well centered point too. I never realized before how hard it is to drill cast iron by the way. I drilled the bolt holes and then milled flat bottom counter sinks for the heads on the vise.
Engraving tip sharpening setup.
Actual Engraving Video
P.S. Previously for another application I had found where a dull rounded drag engraving tip solved a totally different problem.