Inspired by a previous enquiry on here about making nameplates for a Tich I've spend a while working out how to engrave them on my Novamill, and made a couple for the OP. I created the G-code using an excellent program called F-Engrave, which allows to to do text or "V-Carve" from a bitmap image. I created the image in MS Powerpoint and used the "right-click save as image" option to save as a .bmp file.
Here are some photos of the process.
The starting image used by F-Engrave. This translated to about 7000 lines of G-code for the cutting operation (which outlines the letters) and the cleaning operation. Everything black will be cut away to a depth of 1.5mm (3 mm parent material, engraving brass). I used a 1mm diameter TC coated end mill from Arc, which worked out brilliantly, I ordered two cutters and didn't break any! My max spindle speed was ~5000 rpm so I limited the feedrate so it took a long time, about 4 hours per plate.
Setting the tool height so zero is on the top of the plate. I run a macro which lowers the tool until it touches the top of my height setter, backs off, then lowers very slowly 'til it touches again, the raises the tool up to 50mm above the surface the setter is sitting on.
Cutting in progress for the first nameplate.
One down, one to go.
Both plates done, ready for sawing out, cleaning up and painting. I know a lot more about engraving now, but I don't think I'll go into the nameplate business!