Varying zero for cutting on non flat surfaces.

[zonker]

First I hope I have this in the right place and second I hope it hasn't been covered to death. I have searched but I am not sure how to word my search so I might have missed it.
I have a homebuilt cnc router/carver that I have working quite nicely now after months of tweaking(still plan to expand and modify but future plans) it cuts nicely on flat wood and aluminum. What I would like to do however is be able to engrave and carve reliefs on non flat surfaces such as motorcycle engine covers, front forks etc.
Is there a way without breaking the bank to have an sensor of some sort to follow the surface and reset zro onthe fly? or something of a similar nature. I suppose I could sit down and model out each part I am working on and feature mill them but that would be massively time consuming with my rhino/solidworks/mastercam skills and still would miss anything I missed as far as curves go. Is there anyway to approach this for under say $500 or so?

An example would be say I wanted to cut a sheridan style leather pattern into the lower front legs of motorcycle(not perfectly cylindrical).

[M250cnc]

Spring loaded cutter holder could be easy to make depending on what machines you have available.

http://www.2linc.com/

Phil

[zonker]

I appreciate the response but wouldnt that only cut at two levels? either cut or not cut? i would really like to be able to carve more than just engrave.I am planning to make a springloaded one but like I say I would also like to do some actuall carving in cast aluminum stuff.

[HuFlungDung]

I used to use Millwrite 2000 to do some of this sort of work. It had built in wizards to allow you to engrave on certain standard profiles like cylinders, spheres and slopes. Check here:
http://www.hugequestions.com/MillWri...e-v6-demo.html

However, if you have really unique custom surfaces to engrave, you're going to have to model the surface and project the text onto it.

[zonker]

sorry posted twice

[zonker]

Will check out Millwrite, thanks

[DIYaholic]

Take a look at the DIY 3D laser scanners. Perhaps it will allow you to get the shape into your cad/carving program.
Just a newbies $0.02.

[brunog]

Zonker,
A spring loaded cutter could do some carving if you make multiple passes with it..

Best regards

Bruno

[Garfield2]

Probe the surface first to build up an offset mesh of the Z for each X/Y position, then you could script something up to adjust the Z axis offset for the given X/Y position. Hopefully then the Z cut depth would adjust it's "zero" to the probed position taking care of the warped surfaces.

I'm sure I've seen something done like this with PCB engraving on non-flat surfaces using EMC. Can't be sure however.

-A.

[zonker]

I have artcam which will do a feature mill once I have a mesh. I guess I need to dig in to building a touch probe. I think mach 3 has a wizard for running it I am not sure what I would need to get from there to rhino. I guess I'm off to search touch probes.