arc engraving ????

i have been trying to engrave on a arch.....

i cant find any info on how... or what to use

simple example is.....\

got a beer can and i want to engrave my name on it.....
now i know i would have to have 4th axis but .. just a sample

what i want to do is engrave a pistols handle....

the thing is about 30mm width 70 long and the arch is about 4 mm along the 30mm side.....and i want to engrave along the 70mm side so the
angle of the bit shouldn't be bad because the arch is soo small .....
but i just cant figure out how to do it....
im using cambam,autocad,sketchup,artcam, mach3........

can anyone help me plz

or maybe admin can repost this in a proper forum :(

I know that Aspire can project the toolpaths onto a 3D model.

If you're willing to make a probe (or already have one) take a look at G-Code Ripper. Can't beat the price.
G-Code Ripper
Edit/ I'm assuming the pistol grip is an existing piece, not something you're making from stock..
https://www.youtube.com/watch?v=dzX0JXX5iCc