Tips and tricks for shallow milling/ engraving ?

[GEOFFREY]

Thanks Nick, I am aware of what you are saying, I was merely making the point that whilst a fixed projection from a spring loaded toolholder will follow the existing surface and ensure a steady depth below that surface, it will not allow engraving at different depths. I do have a card/vynal cutter that uses exactly that system. G.

[magicniner]

Does a spring loaded cutter with no depth guide allow accurate variable depth engraving over an uneven surface?
Or will changes in surface height change the pre-load on the spring and vary depth?

[GEOFFREY]

When I referred to a fixed projection, I did of course mean a fixed projection from a nosing that touches the surface. G.

[magicniner]

.... not allow engraving at different depths.

So what will?
The OP referred to parts that are not flat, I was responding to the OP with ideas that might help achieve fixed depth on curvy surfaces

[EddyCurrent]

Here's another spring loaded tool
http://www.mrrace.com/SpringTool/index.htm