[paolo6969]

Hey folks - this is driving me to distraction so hopefully someone can help out.

I'm trying to 'photo engrave' a piece of granite. The main issue is that it requires a very shallow cut - say 0.1mm or less. If there's variance of 0.5-1mm over the entire piece there's some obvious problems arising.

There's a few simple - and some quite old - machines that seem to handle this with no problems. Two machines are a GALEKS and GRANITOGRAV - the ones with the angled Z axis. I'm guessing that the angle just makes it a cheaper machine to make as there's no z screw involved.

The Z zero of these machines is set at 1mm. They have a tolerance of 1 to 2 mm in machining depth.

So - two questions I suppose...

1. How do I overcome the tolerance issue?
2. How do the angled Zaxis machine get such good results?

Cheers.

Paolo

[steve323]

Do a search for "auto leveling" and see if the same tricks used for cutting PCB boards would help in your case. It starts with a surface map generated by a touch probe.

Here is an example http://www.cnczone.com/forums/linuxc...are-forum.html

Steve

[paolo6969]

That does look interesting but will have to file it in the library for later.

I'm using a Roland/Techsoft machine so kind of locked into the proprietary control software - no Gcode or Mach3 for me