Tips and tricks for shallow milling/ engraving ?

[magicniner]

http://www.gravograph.us/engraving-p...Nose_Cones.php

By mounting a spindle with this type of nose on a vertical sprung slide (to mimic the original use where hand pressure on a manual pantograph kept it at it's set depth) one can engrave on convex, concave, rippled and non-level surfaces.
The text on this 20mm radius curved Titanium sheet part is about 3mm high -



It's possible to engrave 3 or 4 lines of text on these 20mm radius parts without noticeable depth/width variation.

Geoffrey,
If you want 3D engraving you just set flat parts perfectly level, anything else you model the surface for and then set up your part in exactly the orientation in which it was modelled,
Regards,
Nick

[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