digitize curved surface and engrave it

[turpija]

has anyone come to a solution how to digitize uneven surface and then engrave something on it with automatic Z compensation when and how much required ?

like this amazing datron machine does ...
obviously software automatically calculate required Z compensation ...

video of machine in action is on link
Front panel samples, high speed machining*-*DATRON Dynamics

[svenakela]

Do you know if the panels are bent before or after the engraving? I know curved panels that are bent after the engraving.
Otherwise, that would be a simple task if you have a CAM program.

[turpija]

that's not the problem here ... as it's clearly visible from the attached video panel is bent before engraving, just to demonstrate software capability ... and that part, compensating for unevenness of surface is what bugs me ...

[svenakela]

Ah, didn't even see the video frame before...
But now when I have seen it, it's not magic at all. They even show the pre-digitizing starting in the beginning of the clip. The part is simply digitized and the engraving is Z-level compensated. That could be done with a script for example a inside EMC2 before the milling starts (or outside). They've just included an automatic digitizing procedure. As I said, no magic (and doable even in my workshop).

[turpija]

Interesting, never work with EMC2. I use mach3 ... do you know if it's possible to achieve that Z compensation in mach ?

would it compensate if for instance you have straight line move let's say 100mm, and workpiece is wavy and has few bumps along that line ... would it compensate correctly or just starting and ending coordinates ? is it possible to actually machine a wavy curve along workpiece just with that script ?

[ecurb5]

The part is simply digitized and the engraving is Z-level compensated. That could be done with a script for example a inside EMC2 before the milling starts (or outside).

Can you point me to that script/procedure? I have not been able to find it.

-Bruce

[svenakela]

Can you point me to that script/procedure? I have not been able to find it.

-Bruce

I didn't write that there is a script. I wrote that it could be done with a script.

@turpija, I have very little knowledge about Mach3. I work with Heidenhain and EMC2 operated machines. But Mach3 is pretty configurable so it's probably possible.

I do Z-level compensated profiles, the only difference between my procedure and the one discussed here is that I do it manually (Make profile, digitize, apply curve, post process, mill) and the Datron-guys do it automatically.

[turpija]

Yes that's pretty straightforward ... manual way

what still remain mystery is how to do it automatically ...

let's get little visual, shall we
gray surface is plate that has to be engraved or cutted
red is toolpath created with coordinates from blue spots

without a correction on some parts of board tool would not leave any marks, while on other it might be too deep

what we seen on demonstration video is digitizing a grid of points and then automatically "bending" defined toolpath ... is it even possible to achieve with mach3 ?
has anyone attempt that ?

[CNC-Joe]

This would be great to get working...
I can see digitizing the stock of a hunting rifle or shot gun...
then engraving a nice wildlife scene on it....

Any one make any progress with this concept?

[mcphill]

This would be great to get working...
I can see digitizing the stock of a hunting rifle or shot gun...
then engraving a nice wildlife scene on it....

Any one make any progress with this concept?

Simple to do. Scan the part in with a laser scanner, import the scanned STL in to BobCAM, import artwork, merge with the scan using BobArt, create toolpath, start cutting.

[lwill]

I just stumbled upon this
This has been discussed in this thread:
Cheap & simple height-probing
Intended for PC boards but I made it work to engraving surfaces.
It is for EMC, but you might get the gist of how it is done by looking at the code.