Carving images without cutting surrounding surface

What kind of surface are you trying to save? If for instance you are trying to save live edge bark I would think that would be too thick to compensate in I-Picture settings. If you are just trying to save a stained or the wood patina you could compensate somewhat in the I-Picture settings, However you must remember that I-Picture runs only in "raster" mode like a printer does IE: back and forth along the X axis etc..etc. So you would always be carving a square or rectangle when doing relief images because of this feature. I would suppose that if you had a CAD and design program that could generate GEE code for the machine it could be done that way, However in that program you would have to figure out a way to modify the post processor (assuming we are talking about the 1013 Model) in a way that would slow down the Y or table axis, because it is gear driven it would tend to move too fast in that direction putting lots of stress on the spindle motor, bearing and bit and could cause premature failure of those componets. Unfortunately that is the limitation of the 1013, the 1015 has the ability to move in both "raster" or a random motion because the table is stationary and the gantry which is lead screw driven is what moves along the "Y" axis.

If you are wanting to carve into the piece instead of relief , then what you might try is to set your carve depth at the max which is 1/4" or.250" in I-Picture. When setting up your carve on the machine you would usually set the "Z" down to where it is just barely touching the surface. I would try taking it down to the surface and then bringing it back up about 1.5 mm so that you would only carve the recess. You might have to play around with what is the right height to bring the bit up to do this, I just thought 1.5 mm would be a good place to start. bringing the bit up 1.5 mm would result in something like a 4.7 mm depth of cut for the recessed area. you could do it on a small scrap with 1 letter to try and get the right setting you need.

Thanks Bob, setting the depth to .25 and raising the Z axis slightly above the project did the trick. Carved pefectly

I am only guessing, but I think he wanted the letters to be reccessed into the wood instead of raised relief . Always when I carve the Z is carving out a little of the surface even though the bit might not quite be touching the surface when you setthe origins. If you had some wood that had a patina or stained surface you did want to keep intact, then the prescribed method would do that.